Cladistics
Cladistics (2015) 1–30
10.1111/cla.12136
A large-scale phylogeny of the lycophyte genus Selaginella
(Selaginellaceae: Lycopodiopsida) based on plastid and nuclear loci
Xin-Mao Zhoua,b, Carl J. Rothfelsc,d, Liang Zhanga, Zhao-Rong Hee,
Timothee Le Pechona,f, Hai Heg, Ngan Thi Luh, Ralf Knappi, David Lorencej,
Xing-Jin Heb, Xin-Fen Gaoa,* and Li-Bing Zhangk,*
a
Chengdu Institute of Biology, Chinese Academy of Sciences, PO Box 416, Chengdu, Sichuan 610041, China; bSchool of Life Sciences, Sichuan
University, Chengdu, Sichuan 610064, China; cDepartment of Zoology, University of British Columbia, #4200-6270 University Blvd, Vancouver, BC
V6T 1Z4, Canada; dUniversity Herbarium and Department of Integrative Biology, University of California, Berkeley, CA 94720-2465, USA;
e
School of Life Science, Yunnan University, Kunming, Yunnan 650091, China; fSchool of Life Sciences, University of KwaZulu-Natal, Private Bag
X01 Scottsville, Pietermaritzburg 3209, South Africa; gDepartment of Biology, Chongqing Normal University, Shapingba, Chongqing 400047,
China; hDepartment of Botany, Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, 18th Hoang Quoc Viet Road,
eum national d’Histoire naturelle (MNHN, Paris, France), Steigestrasse 78, 69412
Cau Giay, Ha Noi, Viet Nam; iCorrespondent of the Mus
Eberbach, Germany; jNational Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, HI 96741, USA; kMissouri Botanical Garden, PO
Box 299, St Louis, MO 63166-0299, USA
Accepted 28 June 2015
Abstract
The lycophyte genus Selaginella alone constitutes the family Selaginellaceae, the largest of the lycophyte families. The genus is
estimated to contain 700–800 species distributed on all continents except Antarctica, with highest species diversity in tropical
and subtropical regions. The monophyly of Selaginella in this broad sense has rarely been doubted, whereas its intrageneric classification has been notoriously contentious. Previous molecular studies were based on very sparse sampling of Selaginella (up to
62 species) and often used DNA sequence data from one genome. In the present study, DNA sequences of one plastid (rbcL)
and one nuclear (ITS) locus from 394 accessions representing approximately 200 species of Selaginella worldwide were used to
infer a phylogeny using maximum likelihood, Bayesian inference and maximum parsimony methods. The study identifies
strongly supported major clades and well resolves relationships among them. Major results include: (i) six deep-level clades are
discovered representing the deep splits of Selaginella; and (ii) 20 major clades representing 20 major evolutionary lineages are
identified, which differ from one another in molecular, macro-morphological, ecological and spore features, and/or geographical
distribution.
© The Willi Hennig Society 2015.
The lycophyte family Selaginellaceae contains only
one genus, Selaginella P. Beauv. The largest lycophyte
genus, Selaginella is cosmopolitan and is estimated to
contain 700 (Tryon and Lugardon, 1991), 750 (Jermy,
1990) or ca. 800 species (X.-M. Zhou and L.-B. Zhang,
unpublished data), which inhabit an impressive range of
habitats, including desert, tropical rain forest, and
alpine and arctic habitats. Members of the genus also
have highly diverse growth forms, including erect,
*Corresponding authors:
E-mail addresses: xfgao@cib.ac.cn; libing.zhang@mobot.org
© The Willi Hennig Society 2015
climbing, creeping, prostrate and special rosetting
forms. Many species of Selaginella are medicinally
important and are reported as sources of bioactive compounds (Banks, 2009; Setyawan, 2011; da Silva Almeida
et al., 2013). Recently, the nuclear genome of one species of the genus, Selaginella moellendorffii Hieron., has
been sequenced. This makes the genus enormously
important in studying the evolution of vascular plants,
as the species is the only seed-free vascular plant whose
nuclear genome is known so far (Banks et al., 2011;
Sessa et al., 2014).
2
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Selaginella was established by Palisot-Beauvois (1804)
based on S. selaginoides (L.) P. Beauv. ex Mart. &
Schrank. The genus was characterized by usually having
distinct-sized and dorsiventral leaves in four rows, presenting a ligule at the base of each leaf and sporophyll,
and having heterospores (microspores and megaspores)
and rhizophores (Thomas, 1997). Before Spring’s (1850)
major monograph of the genus, Selaginella was usually
treated as a synonym of another lycophyte genus, Lycopodium L. (Lycopodiaceae) (e.g. Greville and Hooker,
1831). Although the delimitation of Selaginella has
rarely been controversial [but see Rothmaler’s (1944),
Soj
ak’s (1993), Kung’s (1988) and Tzvelev’s (2004) classifications below], the intrageneric classification within
Selaginella has been notoriously contentious (Spring,
1850; Braun, 1857; Hieronymus and Sadebeck, 1901;
Walton and Alston, 1938; Rothmaler, 1944; Tryon and
Tryon, 1982; Jermy, 1986, 1990; Kung, 1988), with taxonomic treatments differing dramatically in the number
of subgenera/sections recognized. In general, previous
authors tended to divide Selaginella into two primary
subdivisions, including the isophyllous versus anisophyllous species, respectively. For example, Spring
(1840) divided the genus into three sections: S. sect. Selaginella (autonym, implied), S. sect. Homoeophyllae
Spring and S. sect. Heterophyllae Spring and similarly
Braun (1857) also recognized three sections but named
them S. sect. Selaginella, S. sect. Dichotropae
A. Braun and S. sect. Homotropae A. Braun, while
Moore (1857) instead used S. sect. Diplostachyum
(P. Beauv.) T. Moore and S. sect. Stachygynandrum (P.
Beauv. ex Mirb.) T. Moore for the latter two. Hieronymus and Sadebeck (1901) also recognized two groups,
but at the rank of subgenus: S. subg. Homoeophyllum
Hieron. & Sadeb. and S. subg. Heterophyllum Hieron.
& Sadeb. Based on morphology (especially that of strobili) and habit forms, Warburg (1900), Walton and
Alston (1938) and Jermy (1986, 1990) subdivided the
genus further. Warburg (1900) recognized five subgenera in the genus: S. subg. Boreoselaginella Warb.,
“S. subg. Euselaginella” (nom. inval., = S. subg.
Selaginella), S. subg. Heterostachys Baker, S. subg.
Homostachys Baker and S. subg. Stachygynandrum (P.
Beauv. ex Mirb.) Baker. Walton and Alston (1938)
accepted Warburg’s (1900) subgenera except S. subg.
Boreoselaginella. Jermy (1986) divided the genus into
five subgenera: S. subg. Selaginella, S. subg. Ericetorum
Jermy, S. subg. Heterostachys, S. subg. Tetragonostachya (Hook. & Grev.) Jermy and S. subg. Stachygynandrum. In addition to the different number of
intrageneric subdivisions recognized by different
authors, the delimitations of these subdivisions have
been controversial and morphological synapomorphies
of most subgenera have remained ambiguous.
While most authors agreed that Selaginellaceae
contain only one genus, a few authors recognized addi-
tional genera in the family. Rothmaler (1944) divided
Selaginella into three genera: Didiclis P. Beauv.,
Lycopodioides Boehm. and Selaginella sensu stricto (s.s.).
The last two were accepted by some later authors (e.g.
Kung, 1988; Sojak, 1993; Tzvelev, 2004). Sojak (1993)
and Weakley (2012) instead recognized Selaginella,
Lycopodiodes and Bryodesma Sojak in the family.
Based on plastid rbcL sequences of 18 species of Selaginella, Korall et al. (1999) conducted the first
molecular analysis of the family, and recovered the
monophyly of the genus and S. subg. Selaginella, and
resolved the latter as sister to the rest of species sampled. Later Korall and Kenrick (2002) increased the
taxon sampling to 62 species and found support for
the monophyly of “S. subg. Tetragonostachys” too,
and identified a so-called “dorsal rhizophoric” clade
that included all species having a distinctive and
unique root-like structure (the rhizophore) emerging
from dorsal surfaces. This later study further discovered the polyphyly of S. subg. Stachygynandrum and
S. subg. Heterostachys, but their analysis was uncertain about the monophyly of S. subg. Ericetorum.
Using nuclear 26S and rbcL data of 23 species, Korall
and Kenrick (2004) resolved the dorsal rhizophoric
clade into two major subclades, although neither of
which is characterized by a clear morphological
synapomorphy. Most recently, based on nuclear ITS
(internal transcribed spacer) and rbcL data of 40
mainly North American species, Arrigo et al. (2013)
confirmed the monophyly of “S. subg. Tetragonostachys” and resolved it as sister to S. lepidophylla
(Hook. & Grev.) Spring, a species native to the Chihuahuan Desert of the USA and Mexico and known
for its ability to survive almost complete desiccation.
Arrigo et al. (2013) showed that the “dorsal rhizophoric’’ clade defined by Korall and Kenrick (2002)
is paraphyletic or polyphyletic.
Notably, previous molecular studies focused mainly
on the two species-poor subgenera only, Selaginella
subg. Selaginella (2 spp.) and “S. subg. Tetragonostachys” (ca. 50 spp.), while S. subg. Heterostachys and
S. subg. Stachygynandrum, which contain a total of
ca. 660 species (Tryon and Lugardon, 1991), were
weakly sampled yet nonetheless were resolved as polyphyletic (Korall et al., 1999; Korall and Kenrick,
2002, 2004; Arrigo et al., 2013), and S. subg. Ericetorum (ca. 8 spp., see below) remains poorly known. In
addition, very few Asian species were included in previous molecular studies, and these studies mainly
tested the five-subgenus classification of Jermy (1986,
1990). Alternative morphological hypotheses of relationship, e.g. the monophyly of S. subg. Homostachys
by Baker (1883, 1887), Warburg (1900), and Walton
and Alston (1938), have rarely been tested. Previous
authors nicely associated various macro-morphological, ecological, physiological and spore features with
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
the monophyletic clades found in their molecular studies (Korall et al., 1999; Korall and Kenrick, 2002,
2004; Arrigo et al., 2013). Still, a large number of
monophyletic clades were supported by molecular
synapomorphies only, mainly because non-molecular
features, e.g. spore morphology, are missing for most
species of Selaginella in spite of tremendous efforts so
far (e.g. Hellwig, 1969; Tryon and Lugardon, 1991;
Korall and Taylor, 2006; Zhou et al., 2015b).
The objectives of this study included: (i) to test the
monophyly of Selaginella using the largest taxon sampling so far and both plastid and nuclear data; (ii) to
resolve the deep-level relationships within Selaginella;
(iii) to identify major evolutionary lineages within
Selaginella by including more Asian species; (iv) to
evaluate the monophyly of S. subg. Heterostachys,
S. subg. Homostachys, S. ser. Rosulatae (A. Braun)
Baker and S. subg. Stachygynandrum and other previous morphology-based hypotheses of relationship
within Selaginella; and (v) to understand morphological synapomorphies for the major lineages resolved by
incorporating newly obtained data, especially those
from spore morphology.
Materials and methods
Taxon sampling
To test the morphological hypotheses about the subgenera, sections, series, subseries and groups previously recognized by various authors (Spring, 1850;
Braun, 1857; Baker, 1883, 1887; Warburg, 1900;
Hieronymus and Sadebeck, 1901; Walton and Alston,
1938; Tryon and Tryon, 1982; Jermy, 1986, 1990;
Kung, 1988; Soj
ak, 1993; Tzvelev, 2004), two or more
species of each of these intrageneric taxa were sampled. We included as many data as possible from GenBank to maximize our taxon sampling and
additionally to draw attention to potential problems
(misidentifications) in the GenBank data, and to invite
further investigations on shallow-level relationships,
cryptic speciation and potential hybridization. We
think this sampling strategy is justified because our
major interest was to identify major evolutionary lineages in the genus and resolve the deep-level relationships among these lineages. All newly included
accessions for which the vouchers were examined by
us or determined by another authority (e.g. Chinese
material by Wei-Ming Chu or Pei-Shan Wang, American material by Michael Windham and/or Alan R.
Smith) are indicated in red and those from GenBank
are indicated in black in our figures. Information on
the geographical provenances of the GenBank accessions are given in the Appendix as much as possible.
Multiple accessions of ca. 130 species were included to
3
represent geographical ranges and intraspecific variations and to test the monophyly of individual species.
In total, 394 accessions representing ca. 200 species
(ca. 30% of the extant diversity of the genus) constituted our ingroup.
The following species were excluded from current
sampling: Selaginella australiensis Baker, S. chuweimingii Xin M. Zhou, Z. R. He, Liang Zhang & Li Bing
Zhang (Zhou et al., 2015a) S. fruticulosa (Bory ex
Willd.) Spring, S. obtusa Spring, S. sinensis (Desv.)
Spring and S. viridula Spring. These species formed a
well-supported clade with long branches in the preliminary analysis but there are no clear morphological
synapomorphies supporting this clade. Korall and
Kenrick (2004) already found this clade but with only
S. australiensis and S. sinensis included. Korall and
Kenrick (2002) postulated possible existence of a pseudogene of rbcL in this clade. More study on these species are needed.
Five species of Iso€
etes (Iso€etaceae), I. kersii Wanntorp, I. kirkii A. Braun, I. nuttallii A. Braun ex
Engelm., I. sinensis Palmer and I. taiwanensis De Vol,
were chosen as outgroups based on the previous findings that Iso€etaceae are sister to Selaginellaceae (Wikom and Kenrick, 1997; Korall et al., 1999) and the
str€
observations that this sister relationship is supported
by the heterospory and ligules in both families (Zhang
and Taylor, 2013; Zhang et al., 2013).
Voucher information and GenBank accession
numbers for each sampled taxon are provided in the
Appendix.
Morphology
Morphological data were obtained from field observations, herbarium investigations and literature study.
Field observations were mainly conducted by the first
author in China and other co-authors in various parts
of the world (C.J.R. in the New World, by L.Z.,
L.-B.Z. and N.T.L. in Vietnam, T.L.P. in La Reunion,
D.L. in the Pacific islands, etc.). Herbarium investigations were carried out at herbaria CDBI, KUN, MO,
PYU and SZ (herbarium acronyms follow Index Herbariorum by Holmgren and Holmgren, 1998).
Spore morphology
The microspore and megaspore morphology of ca.
65 Asian species of Selaginella was observed using a
QUANTA 200 scanning electron microscope (FEI
Co., USA), and the gold–palladium plating was performed using a BAL-TEC SCD 005 cool sputter
coater (BAL-TEC AG., Liechtenstein) at Yunnan
University, Kunming, China. Additional spore morphology data were taken from the literature (see references below).
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
1.0890
0.3310
0.5230
0.2980
0.0000
0.1480
–
–
–
1.0000
1.0000
1.0000
2.2570
4.8722
3.2664
0.5300
0.7545
0.6157
0.5020
2.0448
0.6373
4.6936
3.6505
4.7193
0.5475
1.0251
0.7070
0.2405
0.2596
0.2486
0.2405
0.2702
0.2565
0.2533
0.2889
0.2417
GTR+I+G
GTR+G
GTR+I+G
rbcL gene
ITS
Simultaneous
0.2657
0.1813
0.2532
I
Ti/Tv
G–T
C–T
C–G
A–T
A–G
T
A–C
Substitution model (rate matrix)
G
C
A
AIC selected model
Region
Sequencher 4.1 (Gene Codes Corp., Ann Arbor, MI,
USA) was used to assemble and edit complementary
strands. Sequences obtained for each locus were
aligned using Clustal X 1.81 (Thompson et al., 1997)
followed by manual adjustments using BioEdit (Hall,
1999). The full length of the ITS region was sequenced
in our study. However, as previous studies have
demonstrated (Arrigo et al., 2013; Gu et al., 2013),
ITS1 and ITS2 have a large number of insertions and deletions that could not be aligned with
confidence. Therefore only 5.8S and part of the unambiguously aligned ITS2 region were used; the ambiguous regions were excluded prior to analysis.
Equally weighted maximum parsimony (MP) analyses were conducted for each locus using 1000 treebisection-reconnection (TBR) searches in PAUP* ver.
4.0b10 (Swofford, 2002) with MAXTREES set to
increase without limit. Insertions and deletions were
coded as missing data. Parsimony jackknife (JK) analyses (Farris et al., 1996) were conducted using PAUP*
with the removal probability set to approximately
37%, and “jac” resampling emulated. Two hundred
replicates were performed with 100 TBR searches per
replicate and a maximum of 300 trees held per TBR
search.
Base frequencies
Sequence alignment and phylogenetic analysis
Table 1
Best-fitting models and parameter values for separate (rbcL and ITS) and simultaneous plastid and nuclear datasets in this study
Total genomic DNA was extracted from silica-dried
material or sometimes from herbarium specimens
using a TIANGEN plant genomic DNA extraction kit
(TIANGEN Biotech., Beijing, China) or DNeasy Plant
Mini Kits (Qiagen, Germany) following the manufacturers’ protocols.
One plastid region (the rbcL gene) and one nuclear
region [the internal transcribed spacer (ITS)] were
selected based on their use in earlier studies of Selaginella and allies (Korall et al., 1999; Korall and
Kenrick, 2002, 2004; Arrigo et al., 2013; Gu et al.,
2013; Saha et al., 2013). Most rbcL sequences were
amplified with primers F1 (Fay et al., 1997) and
1379R originally designed by Zurawski et al. (1984)
and modified by Wolf et al. (1999). Internal primers
rbcL-406F, rbcL-770R (Korall et al., 1999) and newly
designed primer rbcL-449F (50 TTGGATACCRTGAG
GYGGRCC30 ) were used when amplification was not
successful. The PCR conditions of rbcL regions followed Zhang et al. (2001) and those of the ITS region
followed Arrigo et al. (2013). Sometimes the reverse
primer ITS-S3R (Gu et al., 2013) was used in ITS
amplification. Amplified fragments were purified with
TIANquick Mini Purification kits (TIANGEN). Purified PCR products were sequenced by Invitrogen
(Shanghai, China).
G
DNA extraction, amplification and sequencing
“G” = gamma distribution shape parameter (Yang, 1994); “GTR” = general-time-reversible model (Tavare, 1986); “I” = proportion of invariable sites; “Ti/Tv” = transition/
transversion ratio.
4
5
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Table 2
Data matrices and tree statistics for each of the analyses
Matrix
No. of
accessions
No. of
characters
No. of PI
characters
(%)*
MPT
length
No. of MP
JK/ML BS
clades
Average MP
JK/ML BS
support (%)
CI
RI
rbcL gene
ITS
Simultaneous
399
278
399
1279
217
1496
666
91
757
4016
980
5611
228/262
90/126
228/265
81/81
76/79
82/83
0.2903
0.2051
0.2436
0.9277
0.8597
0.9056
PI, parsimony-informative; MPT, most parsimonious trees; MP, maximum parsimony; ML, maximum likelihood; JK, jackknife; BS, bootstrap; CI, consistency index; RI, retention index.
*Inclusive of outgroups.
jModelTest 0.1.1 (Guindon and Gascuel, 2003;
Posada, 2008) was used to select the best-fitting likelihood model for maximum likelihood (ML; Felsenstein,
1973) and Bayesian analyses. The Akaike information
criterion (Akaike, 1974) was used to select among
models instead of the hierarchical likelihood ratio test,
following Pol (2004) and Posada and Buckley (2004).
The best-fitting models and parameter values are provided in Table 1.
For each locus and the combined analysis or the
simultaneous analysis (Kluge, 1989; Nixon and Carpenter, 1996) of all nucleotide characters, ML tree
searches and ML bootstrapping were conducted using
the web server RAxML-HPC2 on TG ver. 7.2.8 (Stamatakis et al., 2008; Miller et al., 2010) with 5000
rapid bootstrap analyses followed by a search for the
best-scoring tree in a single run (Stamatakis et al.,
2008).
Bayesian inference (BI) was conducted using
MrBayes 3.1.2 (Huelsenbeck and Ronquist, 2001;
Ronquist and Huelsenbeck, 2003) on Cipres (Miller
et al., 2010). Four Markov chain Monte Carlo chains
were run, each beginning with a random tree and sampling one tree every 1000 generations of 10 000 000
generations. Convergence among generations was
checked using Tracer (Rambaut and Drummond,
2007) and the first 25% of samples were discarded as
burnin. The remaining trees were used to calculate a
50% majority-rule consensus topology and posterior
probability (PP) values.
Results
This study generated 506 new sequences (Appendix).
The dataset characteristics and tree statistics for the
analyses are presented in Table 2. Comparisons of tree
topologies from the MP JK analyses of the individual
markers did not identify any well-supported conflicts
(JK ≥ 70%; Mason-Gamer and Kellogg, 1996; Zhang
and Simmons, 2006; Zhang et al., 2012b, 2015). Thus,
the two datasets were concatenated using MS Excel
2010 (Microsoft, Seattle, WA, USA). The topology of
the ML tree based on the concatenated dataset (Fig. 1)
is mostly identical to those based on each individual
marker, but with generally increased support values.
Based on our reconstructed phylogeny (Figs 1 and
2a–e) and in consideration of macro-morphological,
ecological, and spore features and distribution information, 17 major evolutionary lineages of Selaginella
were identified (Fig. 1). Fourteen of the 17 clades were
well supported (ML BS ≥ 91%, MP JK ≥ 96%, PP ≥
0.99, except for clade XV with MP JK = 88% and
PP = 0.89), while one was weakly supported (clade
XIV: ML BS = 45%, MP JK < 50%, PP = 0.74), and
two were monospecific (clades IV and V). The relationships among the 17 clades except those among
clades III–VI and those among XIV–XVII were well
resolved and strongly supported. Three additional
strongly supported monophyletic superclades within
the genus were identified for descriptive convenience
and for future consideration of taxonomy of the
genus. Superclade A (BS = 100%, JK = 98%, PP =
1.00) contains clades III–VIII, superclade B (BS =
97%, JK = 97%, PP = 0.99) comprises clades X–XIII
and superclade C (BS = 94%, JK = 97%, PP = 1.00)
is composed of clades XIV–XVII.
The ML and BI analyses based on the concatenated
dataset resolved the Selaginella sanguinolenta clade (II)
as the second earliest diverging lineage and is strongly
supported as sister to the rest of the genus except the
S. selaginoides clade (I) (ML BS = 99%, PP = 0.99).
However, in our MP analysis based on the concatenated dataset, the S. sanguinolenta clade (II) was
weakly supported (MP JK = 66%) as sister to the
Rosulatae clade and superclades B+C.
Examples of spore morphology are illustrated in
Fig. 3.
Discussion
The monophyly of Selaginellaceae
As the largest lycophyte family, Selaginellaceae
have long been recognized as sister to Iso€etaceae
6
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
99/100/1.00
XX. S. doederleinii clade (Asia+Australia)
100/100/1.00
XVI. S. oaxacana clade (America)
XVII. S. pallescens clade (America)
45/*/0.74
*/78/1.00
XVIII. S. hartwegiana clade (South America)
Superclade C
100/100/1.00
62/61/*
XIX. S. anceps clade (America)
*/53/0.99
94/97/1.00
OPHA clade
55/61/0.99
60/55/*
Stachygynandrum
superclade
XV. S. involvens clade (Asia)
91/88/0.89
XIV. S. biformis clade (Asia)
91/96/0.99
80/73/0.99
79/69/0.97
S. heterostachys
subclade
100/100/0.99
XIII. Heterostachys clade
Pacific
69/82/0.99
Asia
s. ciliaris
subclade
81/85/1.00
95/87/1.00
97/97/0.99
99/99/0.99
XII. Homostachys clade
82/74/0.97
Superclade B
XI. S. douglasii clade
100/100/1.00
Heterostachys
superclade
94/96/1.00
S. braunii subclade
100/99/0.99
100/91/0.99
X. Oligomacrosporangiatae clade
90/93/0.95
S. willdenowii subclade
100/100/1.00
73/51/0.78
S. delicatula
subclade
S. siamensis subclade
0.05
S. pervillei subclade
S. pennata subclade
100/100/1.00
89/*/0.99
81/82/1.00
S. imbricata subclade
IX. Rosulatae
clade
100/100/1.00
90/97/1.00
S. stauntoniana subclade
100/100/1.00
VIII. S. lepidophylla clade
98/99/0.99
VII. Homoeophyllae clade
100/100/0.99
99/98/1.00
S. kraussiana
subclade
100/100/1.00
100/100/100
Superclade A
S. fragilis
subclade
55/81/0.94
VI. Articulatae clade
100/98/1.00
99/*/0.99
Ericetorum
superclade
V. S. exaltata clade
IV. S. myosurus clade
100/100/1.00
100/100/1.00
III. Lyallia clade
100/100/1.00
II. S. sanguinolenta clade
100/100/1.00
I. S. selaginoides clade
Outgroup
Fig. 1. Simplified maximum likelihood phylogeny of Selaginella based on plastid rbcL and nuclear ITS sequences. The sizes of black triangles
are in proportion to the sampled sizes of individual clades. Support values (maximum likelihood bootstrap support, maximum parsimony jackknife support and posterior probability) are shown along the branches. The 17 major clades and three superclades of Selaginella resolved in this
study are indicated. Green vertical bars indicate superclades or deep-level clades. Blue vertical bars indicate major clades. Black vertical bars
indicate subclades. Red bar indicates outgroups. Purple bar indicates the major clade from America.
7
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
(a)
Figure 2e
Superclade C
Stachygynandrum
superclade
Figure 2d
Superc
Figure 2c
Heterostachys
superclade
Megaspore surfaces reticulate;
Sporophylls usually monomorphic
Megaspore surfaces tuberculate or verrucose;
sporophylls usually dimorphic
Dhofar, Oman
S. imbricata 1
Unknown
S. imbricata 2
S. pilifera
Unknown
S. helioclada
d'Andohahela, Madagascar
d'Andohahela, Madagascar
S. digitata
Unknown
S. stauntoniana 1
S. stauntoniana 2
Henan, China
Beijing, China
S. stauntoniana 3
Okinawa, Japan
S. tamariscina 1
S. tamariscina 2
Unknown
Unknown
S. tamariscina 3
S. pulvinata 1
Sichuan, China
Xizang, China
S. pulvinata 2
lade B
Figure 2b
Homoeophyllae
clade
S. imbricata
subclade
S. stauntoniana
subclade
IX. Rosulatae
clade
Plants xerophytic, rosette, tufted or erect; branches
curled up during drought, megaspore surfaces coarse,
sometimes covered irregularly sized and spaced verrucae
S. lepidophylla
clade
+
S. kraussiana
subclade
S. kraussiana 1
Cult.
S. kraussiana 2
Cult.
Cult.
S. kraussiana 3
S. remotifolia 1
Unknown
Shizuoka, Japan
S. remotifolia 2
S. remotifolia 3
Sichuan, China
Yunnan, China
S. remotifolia 4
Unknown
S. fragilis
Unknown
S. articulata
Stems articulate or with
Unknown
S. sericea 1
swollen joints; only one
Pichincha, Ecuador
S. sericea 2
megasporangium per
Unknown
S. suavis
strobilus on the base;
Unknown
S. sulcata
megaspore surfaces
Heredia, Costa Rica
S. eurynota
reticulate and microspore
Jalisco, Mexico
S. sertata
surfaces spiny
Unknown
S. lingulata
S. arthritica 1
Heredia, Costa Rica
S. arthritica 2
Heredia, Costa Rica
Plants erect and large-sized;
S. silvestris
Heredia, Costa Rica
stems action-plectostely
Puntarenas, Costa Rica
S. kunzeana
Puntarenas, Costa Rica
S. diffusa 1
Cult.
S. diffusa 2
V. S. exaltata clade
Unknown
S. exaltata
S. myosurus
Unknown
IV. S. myosurus clade
Unknown
S. pygmaea
Fianarantsoa, Madagascar
S. lyallii
S. moratii
Fianarantsoa, Madagascar
d'Antsiranana, Madagascar
S. polymorpha
S. gracillima Tasmania, Australia
Tasmania, Australia
S. uliginosa
Dorsal rhizophoric
(except Ericetorum
clade uncertain)
S. fragilis
subclade
VI. Articulatae clade
Superclade A
Ericetorum
superclade
III. Lyallia
clade
S. sanguinolenta 1
S. sanguinolenta 2
S. sanguinolenta 3
S. sanguinolenta 4
Isoëtes nuttallii
Isoëtes kersii
Isoëtes sinensis
Isoëtes taiwanensis
Isoëtes kirkii
Yunnan, China
Sichuan, China
Sichuan, China
Sichuan, China
S. sanguinolenta 5
Unknown
Xizang, China
S. numularifolia
S. deflexa
Hawaii
Nagano, Japan
S. selaginoides 1
S. selaginoides 2
Ontario, Canada
S. selaginoides 3
Unknown
II. S. sanguinolenta clade
Plants xerophytic, creeping; sterile
leaves nearly monomorphic
I. S. selaginoides clade
Plants creeping; megaspore
surfaces reticulate and with
wide and high muri
Megaspore surfaces reticulate;
laesurae of megaspores wing-like
and highly convoluted close to
the pole forming a complex mass
0.05
Plants erect; uniform sterile leaves
and sporophylls spirally arranged
Outgroups
Fig. 2. Maximum likelihood phylogeny of Selaginella based on plastid rbcL and nuclear ITS sequences. Thick lines indicate strong support
(maximum parsimony jackknife support ≥ 75%, maximum likelihood bootstrap support ≥ 75% and posterior probability ≥ 95%), and thin lines
indicate moderate or weak support (either ML BS < 75% or MP JK < 75%). Major diagnostic features are shown in dark blue. Geographical
provenances of newly included samples of Selaginella are indicated in red and those from GenBank are indicated in black. Green vertical bars
indicate superclades or deep-level clades. Blue vertical bars indicate major clades. Black vertical bars indicate subclades. Red vertical bar indicates outgroups. Brown vertical bars in (d) indicate groupings under a subclade. Asterisks in (e) indicate New World species with dimorphic
sporophylls.
using molecular data but based on small taxon sampling (e.g. Wikstr€
om and Kenrick, 1997; Korall et al.,
1999; Pryer et al., 2001). The sister relationship
between these two families is further corroborated by
the shared features of heterospory and the presence
of ligules (Zhang and Taylor, 2013; Zhang et al.,
2013).
The monophyly of Selaginellaceae is supported by
morphology. In comparison with Iso€etaceae, Selaginellaceae species usually have distinctly sized and dorsiventral leaves in four rows and rhizophores
(Thomas, 1997; Zhang et al., 2013). Based on our relatively large sampling and combined analysis of plastid
and nuclear data Selaginellaceae are strongly supported as monophyletic (100% ML bootstrap support
(BS), 84% MP JK) (Figs 1 and 2a).
The monophyly of species, hybridization and cryptic
speciation in Selaginella
Within several clades resolved in our study, such as
the Homoeophyllae clade (VII), the Homostachys clade
(XII) and the S. pallescens clade (XVI), some species
appeared in multiple clades, such as S. densa R. Sim,
S. vardei H. Lev., S. wallacei Hieron. and S. wrightii
Hieron (Fig. 2b). These patterns could be due to
misidentifications, laboratory errors or contamination,
and/or misunderstood species boundaries. As Tryon
(1955) pointed out, there is plasticity in several of the
morphological characters (including those of vegetative
parts, strobili, sporophylls and spores) present in some
sections. Another reason for these seemingly nonmonophyletic species could be the occurrence of
8
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
VIII. S. lepidophylla clade
S. lepidophylla
Unknown
S. lepidophylla
Texas, USA
(b)
With similiar dorsal and ventral
leaves; megaspore surfaces
ridged and reticulate
Spirally arranged monomorphic
sterile leaves; decussate
sporophylls; megaspore surfaces
with interwoven reticulation
S. landii 1
Jalisco, Mexico
California, USA
S. asprella
California, USA
S. leucobryoides 1
Arizona, USA
S. leucobryoides 2
Utah, USA
S. utahensis
Idnho, USA
S. watsonii 1
S. densa 1
British Columbia, Canada
Washington, USA
S. scopulorum 1
S. scopulorum 2
British Columbia, Canada
North Carolina, USA
S. acanthonota
North Carolina, USA
S. rupestris 1
Ontario, Canada
S. rupestris 2
Hokkaido，Japan
S. sibirica 1
Alaska, USA
S. sibirica 2
Utah to Arizona, USA
S. watsonii 2
Illinois, USA
S. rupestris 3
Texas, USA
S. wrightii 1
Hidalgo, Mexico
S. arsenei 1
S. sheldonii
Texas, USA
Oaxaca, Mexico
S. peruviana1
Colorado, USA
S. mutica
Isiolo District, Kenya
S. dregei
S. echinata
Fianarantsoa, Madagascar
S. grisea
Unknown
Tulear, Madagascar
S. nivea
San Luis Potosi, Mexico
S. arsenei 2
Carchi, Ecuador
S. sellowii 1
S. sellowii 2
Florída, Bolivia
Unknown
S. sellowii 3
Boyocá Dept., Colombia
S. sartorii 1
California, USA
S. cinerascens 1
S. cinerascens 2
California, USA
Louisiana, USA.
S. arenicola
Jalisco, Mexico
S. extensa
Colorado, USA
S. weatherbiana
Washington, USA
S. oregana
Tamegdoult, Morocco
S. balansae
S. tortipila 1
South carolina, USA
S. tortipila 2
North Carolina, USA
S. caffrorum
Pretoria, South Africa
Hassan District, India
S. indica 1
S. indica 2
Cult.
Yunnan, China
S. indica 3
S. vardei 1
Sichuan, China
S. vardei 2
Yunnan, China
S. vardei 3
Yunnan, China
Yunnan, China
S. vardei 4
Quezaltenango, Guatemala
S. steyermarkii
California, USA
S. hansenii
California, USA
S. wallacei 1
S. wallacei 2
Oregon, USA
British Columbia, Canada
S. wallacei 3
Oregon, USA
S. wallacei 4
S. bigelovii 1
California, USA
California, USA
S. bigelovii 2
California, USA
S. bigelovii 3
California, USA
S. bigelovii 4
New Mexico, USA
S. mutica var. limitanea 1
Texas, USA
S. mutica var. limitanea 2
New Mexico, USA
S. × neomexicana 1
New Mexico, USA
S. × neomexicana 2
San Luis PotosÌ, Mexico
S. sartorii 2
New Mexico, USA
S. rupincola 1
S. rupincola 2
Arizona, USA
Unknown
S. rupincola 3
Colorado, USA
S. underwoodii
Kwale District, Kenya
S. njamnjamensis
Yunnan, China
S. vardei 5
Nagano, Japan
S. shakotanensis 1
Nagano, Japan
S. shakotanensis 2
Colorado, USA
S. densa 2
S. wallacei 5
Idaho, USA
Washington, USA
S. wallacei 6
Idaho, USA
S. wallacei 7
Texas, USA
S. peruviana 2
Moreles, Mexico
S. landii 2
Texas, USA
S. wrightii 2
Arizona, USA
S. arizonica 1
Unknown
S. arizonica 2
Arizona, USA.
S. arizonica 3
California, USA
S. eremophila 1
S. eremophila 2
California, USA
California, USA
S. eremophila 3
VII. Homoeophyllae clade
Fig. 2. Continued.
S. phillipsiana
Isiolo District, Kenya
S. wightii
Matale District, Sri-Lanka
9
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
S. tama-montana 1
S. helvetica 1
Mie, Japan
Unknown
S. prostrata 1
Sichuan, China
S. prostrata 2
Sichuan, China
Yunnan, China
S. jugorum
S. pallidissima
Sichuan, China
S. laxistrobila 1
Yunnan, China
S. laxistrobila 2
Yunnan, China
S. laxistrobila 3
Yunnan, China
S. helvetica 2
Sichuan, China
S. helvetica 3
Akita, Japan
Unknown
S. denticulata
S. tama-montana 2
Taiwan, China
S. pseudonipponica 1
Taiwan, China
S. pseudonipponica 3
Taiwan, China
S. pseudonipponica 4
S. pseudonipponica 5
Taiwan, China
Taiwan, China
Taiwan, China
S. sp_A
S. nipponica 1
Sichuan, China
S. nipponica 2
Sichuan, China
S. nipponica 3
Sichuan, China
S. nipponica 4
Taiwan, China
Sichuan, China
Taiwan, China
S. matsuensis
S. nipponica 6
Tokyo, Japan
S. pseudonipponica 7
Taiwan, China
Taiwan, China
S. douglasii 1
XI. S. douglasii clade
Native to west of USA; plant creeping; strobili
uniform and megaspore surfaces verrucate
Unknown
Oregon, USA
S. mairei 1
Yunnan, China
S. mairei 2
Yunnan, China
S. mairei 3
Yunnan, China
Sichuan, China
S. braunii 1
Cult.
S. braunii 2
Yunnan, China
S. braunii 3
Hainan, China
S. braunii 4
Hubei, China
Hoa Binh, Vietnam
S. pseudopaleifera
Kagoshima, Japan
S. limbata
S. helferi 1
Yunnan, China
S. helferi 2
Ha Giang, Vietnam
S. helferi 3
Yunnan, China
S. willdenowii 1
Cult.
S. willdenowii 2
Guizhou, China
S. willdenowii 3
Guangxi, China
S. uncinata 1
Peninsula Malaysia
S. uncinata cf.
Puntarenas, Costa Rica
S. uncinata 2
Tokyo, Japan
S. uncinata 3
Sichuan, China
S. mayeri
Peninsula Malaysia
S. plana 1
Cult.
S. plana 2
Cult.
S. hoffmannii 1
S. hoffmannii 2
Puntarenas, Costa Rica
Puntarenas, Costa Rica
Bac Kan, Vietnam
S. wallichii
S. delicatula 1
S. delicatula 2
S. picta 1
S. picta 2
S. picta 3
S. siamensis
S. pennata 2
S.bisulcata 1
S. bisulcata 2
S. bisulcata 3
S. bisulcata 4
S. bisulcata 5
Sichuan, China
Sichuan, China
Phu Tho, Vietnam
Yunnan, China
Yunnan, China
Yunnan, China
S. pervillei
S. pennata 1
Fig. 2. Continued.
Plants xerophytic, erect;
stems with 2 steles, leaves
involute when dry
S. willdenowii subclade
S. mairei 4
Fianarantsoa, Madagascar
Yunnan, China
Yunnan, China
Yunnan, China
Plants scandent and
large; megaspore
surfaces tuberculatereticulate; microspore
distal surfaces twisted
lamellate or with
widely blunt spine
S. delicatula subclade
S. douglasii 2
Plants erect; megaspore
surfaces tuberculate;
microspore surfaces
usually blunt-spiny
Plants xerophytic; megaspore
surfaces regularly verrucose;
microspore surfaces regular
and twisted lamellate
S. siamensis subclade
S. pervillei subclade
Plants erect; leaves on stem
monomorphic, megaspore surfaces
sparsely papillate or tuberculate
Yunnan, China
S. pennata subclade
Yunnan, China
Sporophylls dimorphic;
megaspore exospores smooth
Yunnan, China
Yunnan, China
X. Oligomacrosporangiatae clade
S. pseudonipponica 8
Plants erect, scandent or creeping;
sporophylls monomorphic, except
S. bisulcata and S. pennata
Plants creeping; fertile
branches erect; sporophylls
dimorphic and loose; strobili
non-resupinate
Taiwan, China
S. pseudonipponica 6
S. nipponica 5
XII. Homostachys clade
Taiwan, China
S. pseudonipponica 2
S. braunii
subclade
(c)
10
Fig. 2. Continued.
S. heterostachys
subclade
Native to Asia;
megaspore surfaces
tuberculate or verrucose
Pacific
Sporophylls dimorphic;
strobili resupinate
S. drepanophylla 1
Guizhou, China
S. drepanophylla 2
Guizhou, China
S. chrysocaulos
Sichuan, China
S. labordei 1
Sichuan, China
S. labordei 2
Sichuan, China
S. labordei 3
Sichuan, China
S. labordei 4
Sichuan, China
Sichuan, China
S. sichuanica 1
S. sichuanica 2
Sichuan, China
S. sichuanica cf.
Sichuan, China
S. daozhenensis Guizhou, China
S. megaphylla 1
Hoa Binh, Vietnam
S. megaphylla 2
Ha Giang, Vietnam
S. megaphylla 3
Guizhou, China
S. megaphylla 4
Guizhou, China
S. megaphylla 5
Guizhou, China
S. megaphylla 6
Yunnan, China
S. chaetoloma 1
Yunnan, China
S. chaetoloma 2
Yunnan, China
S. chaetoloma 3
Yunnan, China
S. bodinieri 1
Sichuan, China
S. bodinieri 2
Sichuan, China
S. bodinieri 3
Sichuan, China
S. bodinieri 4
Guizhou, China
S. bodinieri 5
Guizhou, China
Guizhou, China
S. bodinieri 6
S. xichouensis
Yunnan, China
S. kurzii 1
Yunnan, China
S. kurzii 2
Yunnan, China
S. boninensis 1
Tokyo, Japan
S. boninensis 2
Lang Son, Vietnam
S. boninensis 3
Lang Son, Vietnam
S.heterostachys 1
Hainan, China
S.heterostachys 2
Hainan, China
S. heterostachys 3
Guizhou, China
Thai Nguyen, Vietnam
S.heterostachys 4
Lang Son, Vietnam
S.heterostachys 5
Guizhou, China
S.heterostachys 6
Lang Son, Vietnam
S.heterostachys 7
S. heterostachys 8
Guizhou, China
S. heterostachys 9
Mie, Japan
S.heterostachys 10
Sichuan, China
Sichuan, China
S. heterostachys 11
S. heterostachys 12
Hoa Binh, Vietnam
S. sp_B 1
Phu Tho, Vietnam
S. sp_B 2
Ha Giang, Vietnam
S. leptophylla 1
Yunnan, China
S.leptophylla 2
Sichuan, China
S. leptophylla 3
Sichuan, China
S. leptophylla 4
Guizhou, China
S. leptophylla 5
Guizhou, China
S. monospora cf.
Yunnan, China
S. tenuifolia
Bac Kan, Vietnam
S. effusa var. dulongjiangensis
Yunnan, China
S. trichophylla 1
Yunnan, China
S. trichophylla 2
Yunnan, China
S. trichophylla 3
Cao Bang, Vietnam
S. trichophylla 4
Hainan, China
S. amblyphylla 1
Guizhou, China
S. amblyphylla 2
Sichuan, China
S. amblyphylla 3
Sichuan, China
S. decipiens 1
Bac Kan, Vietnam
S. decipens 2
Bac Kan, Vietnam
Vinh Phuc, Vietnam
S. monospora 1
S. monospora 2
Yunnan, China
S. monospora 3
Yunnan, China
S. effusa 1
Guizhou, China
S. effusa 2
Guangdong, China
S. effusa 3
Guizhou, China
S. effusa 4
Guizhou, China
S. sp_ C 1
Guizhou, China
S. sp_ C 2
Guizhou, China
S. sp_C 3
Guizhou, China
S. sp_D
Huahine, Society Is.
S. sp_E
Caroline Is., Kosrae, F.S.M.
S. sp_F
Caroline Is., Kosrae, F.S.M.
S. arbuscula 1
Maui, Hawaiian Is.
S. arbuscula 2
Kauai, Hawaiian Is.
S. kanehirae 1
Caroline Is., Pohnpei, F.S.M.
S. kanehirae 2
Caroline Is., Pohnpei, F.S.M.
S. repanda 1
Yunnan, China
S. repanda 2
Yunnan, China
S. repanda 3
Yunnan, China
S. repanda 4
Yunnan, China
S. albociliata
Guizhou, China
S. lutchuensis
Okinawa, Japan
S. ciliaris 1
Hainan, China
S. ciliaris 2
Peninsular Malaysia
S. xipholepis 1 Guangdong, China
S. xipholepis 2 Bac Kan, Vietnam
S. compta 1
Sichuan, China
S. compta 2
Sichuan, China
S. compta 3
Guizhou, China
S. compta 4
Guizhou, China
S. compta 5
Sichuan, China
S. ciliaris
subclade
Asia
(d)
Megaspores surfaces
usually fine-reticulate
XIII. Heterostachys clade
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
(e)
Plants erect, suberect or creeping;
sterile leaves dimorphic;
megaspore surfaces typically
reticulate, microspore
surfaces usually baculate
OPHA clade
Native to America;
plants suberect or
creeping; megaspore
surfaces reticulate
Fig. 2. Continued.
11
S. biformis 1
Ha Giang, Vietnam
S. biformis 2
Bac Kan, Vietnam
Hainan, China
S. biformis 3
XIV. S. biformis clade (Asia)
Hainan, China
S. biformis 4
Plants flagelliform and erect;
Bac Kan,Vietnam
S. biformis 5
S. biformis 6
Hainan, China
erect plants pubescent
S. biformis 7
Bac Kan,Vietnam
Okinawa, Japan
S. biformis 8
Cult.
S. involvens 1
Phu Tho, Vietnam
S. involvens 2
Yunnan, China
S. involvens 3
Sichuan, China
S. involvens 4
Kagoshima, Japan
S. involvens 5
Yunnan, China
S. involvens 6
S. moellendorffii 1
Sichuan, China
S. moellendorffii 2
XV. S. involvens clade (Asia)
Sichuan, China
S. moellendorffii 3
Sichuan, China
Plants erect or creeping;
Introduced to Costa Rica
S. moellendorffii 4
on veins of ventral leaves
Cult.
S. moellendorffii 5
Beijing, China
S. davidii
with two light color bands
Guizhou, China
S. gebaueriana 1
Yunnan, China
S. gebaueriana 2
Guizhou, China
S. gebaueriana 3
Yunnan, China
S. gebaueriana 4
S. gebaueriana 5
Guizhou, China
S. gebaueriana 6 Yunnan, China
Venezuela
S. novae-hollandiae 1 *
Oaxaca, Mexico
S. oaxacana 1
XVI. S. oaxacana clade
Oaxaca, Mexico
S. oaxacana 2
Heredia, Costa Rica
S. oaxacana 3
(America)
Cult.
S. martensii 1
S. martensii 2
Oaxaca, Mexico
San Luis Potosi, Mexico
S. reflexa
Unknown
S. apoda 1
S. apoda 2
Virginia, USA
Tennessee, USA
S. apoda 3
Unknown
S. acanthostachys
San Luis PotosÌ, Mexico
S. harrisii 1
Cult.
S. pallescens 1
XVII. S. pallescens clade
Hidalgo, Mexico
S. harrisii 2
Cult.
S. pulcherrima
(America)
Unknown
S. pallescens 2
Unknown
S. pallescens 3
S. pallescens 4
San Jose, Costa Rica
Guanacaste, Costa Rica
S. pallescens 5
Hidalgo, Mexico
S. pallescens 6
S. pallescens 7
Guanacaste, Costa Rica
Jalisco, Mexico
S. pallescens 8
Heredia, Costa Rica
S. pallescens 9
San Luis PotosÌ, Mexico
S. nothohybrida
Loja, Ecuador
S. hartwegiana *
XVIII. S. hartwegiana clade
S. novae-hollandiae 2 *
Ecuador
(South America)
S. flexuosa
Zamora-Chinchipe, Ecuador
Guanacaste, Costa Rica
S. anceps 1
Heredia, Costa Rica
S. anceps 2
Carchi, Ecuador
S. microphylla
Unknown
S. haematodes
Cult.
S. erythropus
S. bombycina 1
Heredia, Costa Rica
S.bombycina 2
Unknown
XIX. S. anceps clade
S. radiata *
French guiana
S. attirense cf. 1
Guanacaste, Costa Rica
(America)
S. umbrosa 1
Heredia, Costa Rica
S. umbrosa 2
Cult.
S. flabellata
Lesser Antilles, Grenada
S. flagellata 1 *
Heredia, Costa Rica
S. flagellata 2 *
Unknown
S. simplex *
Unknown
S. moritziana *
Unknown
S. attirense cf. 2
San José, Costa Rica
S. porphyrospora *
San José, Costa Rica
S. alopecuroides
Borneo
S. intermedia
Peninsular Malaysia
S. firmuloides
Unknown
Unknown
S. longipinna
S. kerstingii
Cult.
S. doederleinii 1
Hainan, China
S. doederleinii 2
Kagoshima, Japan
XX. S. doederleinii clade
S. doederleinii 3
Yunnan, China
S. commutata
Guangxi, China
(Asia+Australia)
S. scabrifolia
Hainan, China
S. trachyphylla
Yunnan, China
Plants suberect; megaspore
S. frondosa 1
Unknown
proximal surfaces with a pronounced
S. frondosa 2
Yunnan, China
zona at the equator
S. superba
Yunnan, China
S. roxburghii
Peninsular Malaysia
S. brooksii
Borneo
S. longiaristata
Unknown
12
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
(m)
(n)
(o)
(p)
(q)
(r)
(s)
(t)
(u)
(v)
(w)
(x)
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
hybridization (and possibly allopolyploidy), which has
been reported and postulated earlier in Selaginellaceae
(e.g. Graustein, 1930; Somers and Buck, 1975). Further examples of suspected hybrids in Selaginella
include S. 9 neomexicana Maxon—a possible sterile
hybrid between S. rupincola Underw. and S. mutica
D.C. Eaton (Tryon, 1955; Valdespino, 1993)—and an
unnamed hybrid between S. arizonica Maxon and
S. eremophila (Yatskievych and Windham, 2009).
More studies are needed to better understand the
species-level relationships within these clades with
non-monophyletic species.
Deep-level relationships in Selaginella
Our combined plastid and nuclear data resolve the
deep-level relationships in Selaginella with strong support (Figs 1, 2a and 4). We recognize here six major
deep-level clades (ML BS ≥ 94%, MP JK ≥ 97%,
PP ≥ 0.99): clades I and II, superclades A–C and clade
IX. Clade I (the S. selaginoides clade, see below), containing only two species, was resolved as sister to the
rest of the genus (ML BS = 100%, MP JK = 100%,
PP = 1.00). Clade II (the S. sanguinolenta clade, see
below) is the second earliest diverging lineage (ML
BS = 99%, PP = 0.99), and is a novel deep-level lineage not found in previous molecular studies. Clade
IX (the Rosulatae clade, see below) was found to be
sister to superclades B+C (ML BS = 100%, MP JK =
91%, PP = 0.99), and was not previously recognized
as a deep-level lineage by studies based on either
morphology or molecular data. Below is our detailed
discussion of superclades A–C.
Superclade A—the Ericetorum superclade
The Ericetorum superclade contains clades III–VIII in
our study (Figs 1, 2a and 4). Based on rbcL data alone
Korall and Kenrick (2002) identified a weakly supported so-called “dorsal rhizophoric clade’’ including
S. myosurus Alston, and members of S. ser. Articulatae
(Spring) Hieronymus and Sadebeck (1901) and
“S. subg. Tetragonostachys” sensu Jermy (1986, 1990).
They excluded members of S. subg. Ericetorum sensu
13
Jermy (1986) and three other Malagasy species [S. lyallii
(Hook. & Grev.) Spring, S. moratii Rauh & W. Hagemann, S. polymorpha Badre] from their “dorsal rhizophoric clade”, although these species together were
resolved as sister to that clade. Our analysis, with ca. 88
species included, shows that the “dorsal rhizophoric
clade’’ defined by Korall and Kenrick (2002) is paraphyletic in relation to S. subg. Ericetorum sensu Jermy
(1986) and several other species (Figs 1 and 2b). Our
results are consistent with those of Arrigo et al. (2013)
who sampled 51 species of this clade. We discover a
strongly supported clade (superclade A) containing
S. exaltata, S. lepidophylla, S. myosurus, S. subg. Ericetorum sensu Jermy (1986), S. ser. Articulatae sensu
Hieronymus and Sadebeck (1901), “S. subg. Tetragonostachys” sensu Jermy (1986), and three Malagasy
species (S. lyalii, S. moratii, S. polymorpha). The most
parsimonious interpretation would be that dorsal rhizophores evolved once in the most recent common
ancestor of superclade A and this character state was
lost in the Lyallia clade (III). Here we advocate recognition of this expanded “S. subg. Tetragonostachys” as a
subgenus of Selaginella (Fig. 4). Based on our estimate
superclade A contains ca. 200 species, while “S. subg.
Tetragonostachys” sensu Jermy (1986) contains ca. 50
species only. Such an expanded “S. subg. Tetragonostachys” differs from the rest of the genus by the dorsal
rhizophoric (except clade III), and includes the xeromorphic isophyllous species, the articulate species, the
species with monomorphic and decussately arranged
leaves, and a rosette-forming species [S. lepidophylla
(Hook. & Grev.) Spring].
Within superclade A, the S. lepidophylla clade (VIII)
is resolved as sister to the Homoeophyllae clade (VII),
and they together are sister to a clade containing
clades III–VI. Our study resolves superclade A as sister to a clade containing clade IX (the Rosulatae clade)
and superclades B and C with strong support (ML
BS = 89%, PP = 1.00).
Superclade B—the Heterostachys superclade
The Heterostachys superclade contains clades
X–XIII in our study (Figs 1 and 2c,d). In the previous
Fig. 3. Scanning electron micrographs of megaspores and microspores of selected species of Selaginella (see Zhou et al., 2015b for more details).
(a–q) megaspore morphology of the major clades and subclades; (r–x) microspore morphology of clade XIII, the Heterostachys clade. (a)
S. sanguinolenta (L.) Spring (clade II), Chu & Wu 68 (PYU). (b) S. remotifolia Spring (clade VI), Chu & Zhang 20188 (PYU). (c) S. vardei H. Lev.
(clade VII), Jin & Cao s.n. (PYU). (d) S. stauntoniana Spring (clade IX), PYU 870080 (PYU). (e) S. nipponica Franch. & Sav. (clade XII), Chu 4753
(PYU). (f) R, S. braunii Baker (clade X: the S. braunii subclade), Chu & Wu 3043 (PYU). (g) S, S. willdenowii (Desv. ex Poir.) Baker (clade X: the
S. willdenowii subclade), Chu et al. 18474 (PYU). (h) T, S. picta A. Braun ex Baker (clade X: the S. delicatula subclade), Lu & Zou 18748 (PYU). (i)
U, S. siamensis Hieron. (clade X: the S. siamensis subclade), Chu et al. 15741 (PYU). (j) V. S. pennata (D. Don) Spring (clade X: the S. pennata
subclade), Chu & Zhang 24587 (PYU). (k) W, S. kurzii Baker (clade XIII: the S. heterostachys subclade), Chu 3833 (PYU). (l) X, S. ciliaris (Retz.)
Spring (clade XIII: the S. ciliaris subclade), Chu et al. 15426 (PYU). (m) S. biformis A. Braun ex Kuhn (clade XIV), Chu et al. 23504 (PYU). (n)
S. involvens (Sw.) Spring (clade XV), Chu & Feng 51 (PYU). (o) S. gebaueriana Hand.-Mazz. (clade XV), Chu & Feng 89 (PYU). (p,q) S. commutata
Alderw. (clade XVII), Zhou 2441 (PYU). (A) The obviously disconnected laesurae at the pole in the Homostachys clade. (B) The extremely smooth
exospore in the S. pennata subclade. (C) The equatorial flange in S. involvens. (D) The zona at equator in the S. doederleinii clade.
14
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Stachygynandrum
Heterostachys
Lycopodiodes
ventral rhizophores
Stachygynandrum
Sta
S Sta Er
Sta
Tetragonostachys
S
Lycopodiodes
Bryodesma
dorsal rhizophores
nr vr ?
I
II
III IV V
VI
VII
A: Ericetorum
VIII
IX
He
X
XI
XII
B: Heterostachys
XIII
XIV
XIX XVIII XVII XVI XX
XV
C: Stachygynandrum
(a)(b) (c) (d)(e)
classifications of Selaginella, S. subg. Heterostachys
comprised the species with dimorphic, resupinate
sporophylls (Baker, 1884, 1887; Warburg, 1900; Walton and Alston, 1938; Jermy, 1986, 1990). Previous
molecular studies (e.g. Korall and Kenrick, 2002) sampled only a few species (all from the Americas), but
S. subg. Heterostachys sensu Baker contains ca. 60
species (Jermy, 1990) and is distributed globally in the
tropics (Tryon and Lugardon, 1991). Asia is the major
distribution area with more than 28 species in China
(Zhang et al., 2013) and more than 25 species in India
(Alston, 1945). In our study, 167 accessions respresenting ca. 80 species form the strongly supported monophyletic superclade B (which we advocate recognizing
as the expanded S. subg. Heterostachys), which contains members of S. subg. Heterostachys sensu Baker
(1883, 1887), S. subg. Homostachys sensu Baker (1883,
1887), Warburg (1900), and Walton and Alston
(1938), S. ser. Suberosae (Baker) Warb., the tropical
and subtropical species with uniform sporophylls, and
S. douglasii (Hook. & Grev.) Spring. In other words,
superclade B contains all species with dimorphic
sporophylls from Asia and the Pacific islands and
some species with uniform sporophylls from tropical
and subtropical regions (e.g. S. braunii, S. delicatula,
S. hoffmannii, S. pervillei, S. siamensis, S. uncinata)
and temperate S. douglasii.
Species of the Heterostachys superclade appear
highly variable in morphology and geographical distribution. They can have various habits (erect, scandent,
creeping or prostrate) and strobili (with uniform
sporophylls, or dimorphic non-resupinate or resupinate
sporophylls) and grow in various habitats. However,
species of this superclade share some megaspore features. Their megaspore surfaces are tuberculate, sometimes papillate, verrucate and rugulate. In some cases,
these megaspore ornamentations combine with each
other and even form irregular reticulate ornamentations although completely different from the reticulate
ornamentations in S. subg. Stachygynandrum (Fig.
3e–l vs. m–q).
Our study resolves superclade B as sister to superclade C with relatively strong support (ML BS = 80%,
Fig. 4. Simplified maximum likelihood phylogeny of Selaginella
based on plastid rbcL and nuclear ITS sequences. (a) 20 major lineages. (b) three superclades. (c) five-subgenus classification of Jermy
(1986). Clade III, marked as Er (= S. subg. Ericetorum = the Lyallia
clade), contains three species (S. lyallii, S. moratii, S. polymorpha)
classified in Stachygynandrum. Clade XVI, marked as Stachygynandrum, contains some species classified in Heterostachys as well.
s = S. subg. Selaginella; Sta = S. subg. Stachygynandrum; He =
S. subg. Heterostachys. (d) the three-genus classification of Sojak
(1993). (e) rhizophores. vr = ventral rhizophores. nr = no rhizophores. ? = the Lyallia clade, where rhizophore position is difficult
to determine.
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
MP JK = 75%, PP = 0.99). Within superclade B, the
S. douglasii clade (XI) is resolved as sister to the
Homostachys clade (XII), together they are sister to
the Oligomacrosporangiatae clade (X) and the three
together are sister to the Heterostachys clade (XIII).
Superclade C—the Stachygynandrum superclade
The Stachygynandrum superclade contains clades
XIV–XX (Fig. 2e). Traditionally all species of Selaginella with dimorphic leaves and uniform strobili
were included in S. subg. Stachygynandrum (P. Beauv.)
Baker (e.g. Baker, 1887; Warburg, 1900; Walton and
Alston, 1938; Jermy, 1986, 1990). However, a molecular phylogenetic study has demonstrated that S. subg.
Stachygynandrum is not monophyletic (Korall and
Kenrick, 2002), a result confirmed in our study
(Fig. 4). We find a narrowly defined S. subg.
Stachygynandrum s.s. that is supported as monophyletic (ML BS = 94%, MP JK = 97%, PP = 1.00),
and which corresponds to our superclade C. This subgenus in our definition includes the members of
S. subg. Stachygynandrum sensu (P. Beauv.) Baker
(1883) excluding the species of S. ser. Articulatae
(Spring) Hieron. & Sadeb., S. ser. Rosulatae sensu (A.
Braun) Baker and S. ser. Suberosae sensu (Baker)
Warb. This newly circumscribed subgenus may contain
200 species and is characterized by plants that are
erect, suberect or creeping, megaspore surfaces that are
reticulate (Fig. 3m–q), and microspore surfaces usually
baculate (Liu et al., 1989; Korall and Taylor, 2006; Xia
et al., 2013; Singh et al., 2014; our own observations).
Within Selaginella subg. Stachygynandrum s.s., 88
accessions representing ca. 50 species in our analysis
are resolved into four clades (clades XIV–XVII;
Fig. 2e), three of which are well supported. The S. biformis clade (XIV) is sister to the remaining three, followed by the S. involvens clade (XV) which is sister to
a clade containing the OPHA clade (clades XVI–XIX)
and the S. doederleinii clade (XX) (see discussion
below).
Major evolutionary lineages in Selaginella
The ca. 200 species of the genus sampled in our
study are resolved into the following 20 well-supported
(except one weakly supported) major clades including
two currently monospecific clades (Fig. 1). All of these
major clades are also supported by macro-morphological, ecological, and/or spore features and/or distribution information.
Clade I—the Selaginella selaginoides clade
Clade I corresponds to Selaginella subg. Selaginella
and contains only two species: the circumboreal
15
S. selaginoides (L.) P. Beauv. ex Schrank & Mart.
(Jermy, 1990) and the Hawaiian endemic S. deflexa
Brack. (Jermy, 1986). The former is also the type of
the genus. In earlier classifications, although the close
relationship between the two species had long been
recognized, the subgenus was often lumped with other
isophyllous species, e.g. in S. sect. Homoeophyllae
Spring by Spring (1850), in S. sect. Homotropae by
Braun (1857), in S. sect. Cylindrostachyae by Hieronymus and Sadebeck (1901) and in “S. subg. Euselaginella” (nom. inval.) by Walton and Alston (1938).
Conversely, Baker (1883, 1887) accepted S. subg. Selaginella, but his concept of the subgenus included all
isophyllous species. Also, S. subg. Selaginella sensu
Tryon and Tryon (1982) contains about 50 species but
our study shows that it contains only two species.
We sampled both species in our analysis, which
shows that S. subg. Selaginella is strongly supported
as monophyletic (ML BS = 100%, MP JK = 100%,
PP = 1.00). For the first time multiple samples of
S. selaginoides are included, which supports the monophyly of this species. Selaginella subg. Selaginella is
robustly supported as sister to the rest of the genus
(ML BS = 100%, MP JK = 100%, PP = 1.00), which
is consistent with the findings of Korall and Kenrick
(2002) and Arrigo et al. (2013). This subgenus is characterized by plants erect, uniform leaves and sporophylls spirally arranged, and the chromosome number
(of S. selaginoides) of 2n = 18 (Heidel and Handley,
2006).
Two characteristics of S. subg. Selaginella (determinate growth and rootstock) have been interpreted as
support for a closer relationship to Iso€etales than to
other species of Selaginellaceae (Bateman, 1992; see
alternative interpretation in Kenrick and Crane, 1997,
pp. 212–213).
Clade II—the Selaginella sanguinolenta clade
The Selaginella sanguinolenta clade (II) contains Selaginella sanguinolenta (L.) Spring and its allies (an
additional three or four species based on our estimate).
Because of the nearly monomorphic sterile leaves, the
relationships of this subgenus had been controversial.
Spring (1850) placed it in S. sect. Homoeophyllae with
the other isophyllous species. Baker (1883, 1887) and
Warburg (1900) also placed it together with isophyllous species in S. subg. Selaginella. Hieronymus and
Sadebeck (1901) placed in it S. subg. Heterophyllum
sect. Pleiomacrosporangiatae ser. Monostelicae with
dimorphic sterile leaves and thought that the nearly
monomorphic sterile leaves may be intermediate
between S. subg. Heterophyllum and S. subg. Homoeophyllum. Walton and Alston (1938) placed in it
S. subg. Stachygynandrum ser. Decumbentes with
dimorphic sterile leaves and hypothesized that it is an
16
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
intermediate stage between S. subg. Stachygynandrum
ser. Decumbents and “S. subg. Euselaginella”. In addition to the nearly monomorphic sterile leaves, members of this clade have megaspore surfaces with
densely contiguous tubercles (Fig. 3a) and microspore
surfaces rugulate and tuberculate (for spore morphology of S. sanguinolenta also see Minaki, 1984; Liu
et al., 1989; for that of S. nummularifolia see Liu and
Yan, 2005).
Members of the Selaginella sanguinolenta clade were
not previously included in a phylogenetic study. We
included two species in our analysis, S. sanguinolenta
(L.) Spring with a broad Asian distribution and
S. nummularifolia Ching endemic to Xizang, China.
The monophyly of this clade is strongly supported
(ML BS = 100%, MP JK = 100%, PP = 1.00).
Based on our ML and BI analyses, the Selaginella
sanguinolenta clade (II) is the second earliest diverging
lineage and is strongly supported as sister to the rest
of the genus except the S. selaginoides clade (I) (ML
BS = 99%, PP = 0.99). However, in our MP analysis,
the S. sanguinolenta clade (II) was weakly supported
(MP JK = 66%) as sister to the Rosulatae clade and
superclades B+C. This conflict was first found by Korall and Kenrick (2004) in Selaginella. Potentially, this
could be caused by GC-rich plastid DNA in Selaginella (Smith, 2009). As Eyre-Walker (1998)
showed, parsimony analyses may encounter problems
when resolving the phylogenies which contain biased
base composition. In other words, MP may be extremely sensitive to nucleotide composition (Smith, 2009).
Based on spore morphology (Liu et al., 2002) and
habit, Selaginella kashminiana Dixit from Pakistan
may be a member of this clade.
Clade III—the Lyallia clade
The Lyallia clade (III) contains six species. In our
analysis, two Australian species [Selaginella gracillima
(Kuntze) Alston and S. uliginosa (Labill.) Spring] and
four Afro-Madagascar species (S. lyallii, S. moratii,
S. polymorpha and S. pygmaea Alston) form a
strongly supported monophyletic clade (ML BS =
100%, MP JK = 100%, PP = 1.00), and the Australian species together are sister to the Afro-Madagascar species, consistent with the results of Korall and
Kenrick (2002) that. Selaginella subg. Ericetorum sensu
Jermy (1986) containing S. gracillima, S. pygmaea and
S. uliginosa is paraphyletic in relation to the four
Afro-Madagascar species (Fig. 2a).
Although the three species of Selaginella subg. Ericetorum sensu Jermy (1986, 1990) are different from the
three Malagasy species (S. lyallii, S. moratii, S. polymorpha) in morphology and habit (Korall and Kenrick, 2002), these six species share some morphological
and spore features: (i) the megaspore surfaces are reticulate and have wing-like and highly convoluted laesurae forming a complex mass at the pole (Stefanovic
et al., 1997; Korall and Taylor, 2006; Schulz et al.,
2013); (ii) microspores are globose-triangular, and
their proximal surfaces are coarse, sometimes covered
with fine spines and the distal surfaces are usually regulate (for microspore morphology of S. pygmaea, see
Schulz et al., 2013; for that of S. moratii and S. polymorpha, see Stefanovic et al., 1997); (iii) although the
Malagasy species have dimorphic sterile branch leaves,
their monomorphic and decussately arranged sterile
stem leaves are consistent with members of S. subg.
Ericetorum sensu Jermy (1986); (iv) rhizophores are
strictly restricted to the base of erect stems within all
members of the Lyallia clade; and (v) these species
have the same chromosome number 2n = 18 as far as
known [(S. uliginosa and S. lyallii were examined by
Jermy et al. (1967)].
Note that Schulz et al. (2013) segregated Selaginella
pygmaea into two species, S. aboriginalis C. Schulz &
Homberg (from Australia) and S. pygmaea (from
South Africa), and added S. royenii Alston from
southern New Guinea, Indonesia, to this clade
(S. subg. Ericetorum). So, the Lyallia clade probably
includes eight species: four Australasian ones (S. aboriginalis, S. gracillima, S. uliginosa, S. royenii) and
four Afro-Madagascar ones (S. lyallii, S. moratii,
S. polymorpha, S. pygmaea).
Korall and Kenrick (2002) excluded members of Selaginella subg. Ericetorum sensu Jermy (1986) from
their “dorsal rhizophoric clade”. However, because
these three species have erect stems and the rhizophores are strictly at the base, it is not easy to assess
accurately if these three species have dorsal
rhizophores (Fig. 4).
Clade IV—the Selaginella myosurus clade
The Selaginella myosurus clade (IV) contains only
the western African S. myosurus in our sampling.
Judging from morphology, S. scandens (P. Beauv.)
Spring from Gabon might belong to this clade. In our
analysis, S. myosurus is resolved as sister to the Lyallia
clade but with weak support. Hieronymus and Sadebeck (1901) placed S. scandens and S. puberula
Klotzsch from Guiana together in the S. scandens
group, so S. puberula may also be in this clade.
Based on its creeping habit, a single large megasporangium on the base of strobili, dorsal rhizophores
(our observations), megaspore surfaces reticulate, and
wide and high muri (Korall and Taylor, 2006),
S. myosurus should be close to the Articulatae clade,
but our study resolves this species outside of that
clade, but without support.
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Clade V—the Selaginella exaltata clade
The Selaginella exaltata clade (V) contains only
Central and South American species in our sampling.
Hieronymus and Sadebeck (1901) established the
monospecific S. exaltata group, one of the four groups
under their S. subser. Monostelicae. This subseries also
included S. kraussiana (Kunze) A. Braun, S. remotifolia Spring, etc. Our study resolves S. exaltata (clade V)
away from S. kraussiana and S. remotifolia, etc. (clade
VI), but without support (Fig. 2a); it is possible that
additional data will demonstrate that S. exaltata is sister to S. kraussiana and its allies. Morphologically and
anatomically, S. exaltata has large erect plants (up to
1 m) and has several steles in a special actino-plectostele (a sort of three-lobed plectostele) and extremely
large megaspores (ca. 1.5 mm) (Mickel and Hellwig,
1969), which are different from members of the Articulatae clade. With denser future samples, possibly more
members of the S. exaltata clade will be identified.
Clade VI—the Articulatae clade
The Articulatae clade (VI) approximates Selaginella
ser. Articulatae (Spring) Hieronymus and Sadebeck
(1901). Morphologically, members of the series share
the following features: (i) below bifurcation of the
stem there are articulations or swollen joints; (ii) rhizophores are borne on the dorsal side of the stems;
(iii) a single large megasporangium is located at the
base of a strobilus; (iv) megaspore surfaces have irregular or regular (Fig. 3b) and coarse reticulum usually
with high and wide muri (e.g. Minaki, 1984; Liu et al.,
1989, 2006; Giorgi et al., 1997; Korall and Taylor,
2006; Xia et al., 2013); (v) megaspores are extremely
large; and (vi) microspore surfaces usually have spines
(e.g. Hellwig, 1969; Tryon and Lugardon, 1991; Giorgi
et al., 1997; Xia et al., 2013). In our study, the 22
accessions included in the Articulatae clade are
strongly supported as monophyletic. Previous classifications placed members of this clade among other
anisophyllous groups. Our study shows, instead, that
they have closer relationships with isophyllous taxa.
Within the clade the S. kraussiana subclade is
strongly supported as sister to the S. fragilis subclade.
Members of the first subclade occur in Asia and
Africa, while those of the second subclade occur in the
Americas. These two subclades have no significant differences in morphology, habit or number of chromosomes. Although the number of vascular bundles is
mainly one in Selaginella, it also shows great variation
in some groups (such as the Oligomacrosporangiatae
clade, see below) (Chu, 2006). In the Articulatae clade,
the number of vascular bundles ranges from one to
five, and usually two (Walton and Alston, 1938; Korall
and Kenrick, 2002). Within the S. kraussiana subclade,
17
S. kraussiana has one vascular bundle while S. remotifolia has two (Zhang, 2004; Chu, 2006; our own observations). The members of the S. fragilis subclade have
from one to more vascular bundles.
Clade VII—the Homoeophyllae clade
The Homoeophyllae clade (VII) approximates “Selaginella subg. Tetragonostachys” sensu Jermy (1986),
which contains ca. 45–60 species distributed across the
Old and New Worlds except Australia (Tryon and
Lugardon, 1991), and most species occupy xeric habits
(Tryon, 1955; Arrigo et al., 2013). Previous studies
(Korall and Kenrick, 2002, 2004; Arrigo et al., 2013)
pointed out that there is little doubt about the monophyly of “S. subg. Tetragonostachys” sensu Jermy, and
its sister relationship with the resurrection plant
S. lepidophylla has been strongly supported. Our study
further corroborates these results. Morphologically,
members of “S. subg. Tetragonostachys” share spirally
arranged monomorphic leaves and decussate sporophylls (Jermy, 1986; Sojak, 1993). Megaspore surfaces
of members of this clade have an interwoven, closed,
irregular and fine reticulum (Fig. 3c), and sometimes
the muri are not obvious (e.g. Tryon, 1949; Minaki,
1984; Liu et al., 1989; Chu, 2006; Korall and Taylor,
2006; Zhu et al., 2006; Xia et al., 2013). The megaspore morphology is stable and unique to the Homoeophyllae clade. The microspore proximal surfaces have
rough and irregular rugulate ornamentation and distal
surfaces are verrucate and rugulate (Liu et al., 1989;
Chu, 2006; Zhu et al., 2006; Xia et al., 2013).
Within the Homoeophyllae clade the relationships
are poorly resolved.
Clade VIII—the Selaginella lepidophylla clade
The Selaginella lepidophylla clade (VIII) contains ca.
four species including the American species S. lepidophylla (Hook. & Grev.) Spring. The clade is resolved
as sister to the Homoeophyllae clade with strong support. This sister relationship of the two clades is supported by their shared xerophytic ecologies. Based on
the rosulate and xerophytic habit, S. lepidophylla was
usually placed in the resurrection group, the Rosulatae
clade (see below), but our study shows that the S. lepidophylla clade and the Rosulatae clade are not closely
related (Fig. 2b).
Morphologically, the S. lepidophylla clade also has
some particular features, such as plants having similar
dorsal leaves and ventral leaves (Mickel and Smith,
2004), distal surfaces of the megaspores having high
ridges and proximal surfaces being reticulate forming
connected ridges (Korall and Taylor, 2006), and
microspores scattering in tetrads surrounded and ornamented by several ridges (Hellwig, 1969; Giorgi et al.,
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Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
1997; Mickel and Smith, 2004). Therefore, the S. lepidophylla clade is morphologically distinct from both
the Rosulatae clade (IX) and the Homoeophyllae clade
(VII). Mickel and Smith (2004) also thought that
S. lepidophylla was different from the Rosulatae clade.
Based on their judgment two species (S. novoleonensis
Hieron. and S. ribae Valdespino) from Mexico might
belong to the S. lepidophylla clade. Morphologically,
their plants all have similar dorsal and ventral leaves
and share the rosette-forming habit.
Clade IX—the Rosulatae clade
The Rosulatae clade (IX) approximates Selaginella
ser. Rosulatae (A. Braun) Baker (1883), and contains at
least 12 species. Members of this clade occur in seasonally dry areas and are rosette, tufted or erect plants.
Their branches curl up during drought (“resurrection
plants”) and the ventral leaves usually have a membranous and lacerate margin. Their megaspores have a
coarse surface and irregularly sized and spaced verrucae
(Fig. 3d) (e.g. Minaki, 1984; Liu et al., 1989; Korall and
Taylor, 2006; our own observations) and their microspores are globose (Liu et al., 1989; our own observations). Although the rosette form is also present in other
species, such as S. lepidophylla (see above) and
S. pallescens (C. Presl) Spring, the megaspore surfaces
of these species are entirely different from those of the
Rosulatae clade. The megaspores of S. pallescens have
very fine reticulate ornamentation, while the proximal
surfaces of the megaspores of S. lepidophylla are reticulate and the distal surfaces have coarse, sparse, hamulate, and high and wide ridges (Korall and Taylor,
2006). The rosette form appears to have independently
evolved at least three times, once in the S. lepidophylla
clade, in S. pallescens and in the Rosulatae clade.
Our study, with eight Old World species and one
New World species included, shows that Selaginella
subg. Rosulatae is strongly supported as monophyletic,
consistent with the result of Korall and Kenrick
(2002). This clade is strongly supported as sister to
superclades A+B, which also have dimorphic leaves.
Within the Rosulatae clade, the Asian species (the
S. stauntoniana subclade) are resolved as sister to those
from the Arabian Peninsula, Africa/Madagascar, and
North America (the S. imbricata subclade) (ML
BS = 100%, MP JK = 100%, PP = 1.00).
Baker (1884) included Selaginella convoluta (Arn.)
Spring (America), S. bryopteris (L.) Baker (India),
S. pringlei Baker (Mexico), etc., in this clade. Further
data will be necessary to test these hypotheses.
Clade X—the Oligomacrosporangiatae clade
The Oligomacrosporangiatae clade (X) presents a
complex group. Members of this clade show numerous
variations [chromosome number, habit, habitat, number of stele, sporophylls, and megaspore (Fig. 3f–j)
and microspore (Fig. 3r–v) morphology]; understanding relationships within this clade is difficult because
of the complexity of features exhibited and the poorly
resolved phylogeny we obtained (Fig. 2c).
Within the Oligomacrosporangiatae clade, the 41
accessions representing ca. 30 species in our sampling
are resolved into six subclades: the S. braunii subclade,
the S. delicatula subclade, the S. pennata subclade, the
S. pervillei subclade, the S. siamensis subclade and the
S. willdenowii subclade. All of these subclades are
strongly supported as monophyletic except the
S. delicatula subclade whose monophyly is moderately
supported, and the S. siamensis subclade and the
S. pervillei subclade, which are monospecific in our
sampling.
The Selaginella braunii subclade
This subclade contains two xerophytic species,
S. braunii Baker and S. mairei H. Lev. The first species was assigned to S. ser. Caulescentes Baker (1887)
and both were assigned to the same series by Walton
and Alston (1938). Morphologically, the two species
are erect plants with monomorphic sterile leaves on
the main stem and dimorphic leaves on branches,
involute leaves when dry, and two-banded steles
(although the stem has only one “X”- or “V”-shaped
vascular bundle in S. mairei, its rhizome clearly has
two vascular bundles) (Chu, 2006). These morphological features are not present in other subclades in the
Oligomacrosporangiatae clade.
Megaspore surfaces are tuberculate, papillate and
verrrucate, and these elements are usually combined
(Fig. 3f), and microspores have broadly blunt
spines, sometimes lamellate (Fig. 3r) (e.g. Liu et al.,
1989, 2006; Zhou et al., 2012; Xia et al., 2013).
Walton and Alston (1938) thought that those species
(such as S. biformis A. Braun ex Kuhn, S. moellendorffii) with monomorphic sterile stem leaves were closely related, a hypothesis rejected by our study that
shows that these species are scattered in different
major clades.
The Selaginella delicatula subclade
This subclade contains six Asian species and a Central American species (S. hoffmannii Hieron.) in our
current sampling. The subclade is divided into two
strongly supported clades—the S. plana grouping [including S. hoffmannii Hieron., S. mayeri Hieron.,
S. plana (Desv. ex Poir.) Hieron.] and the S. delicatula
grouping [including S. delicatula, S. picta A. Braun ex
Baker and S. wallichii (Hook. & Grev.) Spring]
(Fig. 2c). Having three vascular bundles (the number
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
of vascular bundles in S. hoffmannii and S. mayeri is
unknown) and entire or subentire leaves, this subclade
is similar to the S. willdenowii subclade (see below).
The members of this subclade are erect or suberect
(except S. mayeri), with megaspore surfaces typically
tuberculate (Fig. 3h), sometimes combined (e.g. Minaki, 1984; Chang et al., 2002a; Korall and Taylor,
2006; Xia et al., 2013; Singh et al., 2014), and microspore surfaces usually bluntly spiny (Fig. 3t) (e.g. Hellwig, 1969; Chang et al., 2002b; Xia et al., 2013),
different from the members of the S. willdenowii subclade. Note that three of the members of the S. delicatula subclade, S. delicatula, S. plana and S. wallichii,
have the chromosome number 2n = 20 (Kuriachan,
1963; Jermy et al., 1967), while the S. willdenowii
subclade has 2n = 18 (see below). These features all
corroborate our result that the two subclades are not
closely related.
Within the Selaginella delicatula subclade, S. hoffmannii is unique in terms of morphology and geography: it is distributed in the Americas and its leaves
have ciliate margins.
The Selaginella pennata subclade
This subclade is strongly supported as monophyletic
(ML BS = 100%, MP JK = 100%, PP = 1.00) and
contains two species [S. bisulcata Spring and S. pennata (D. Don) Spring] in our sampling. These two species are very similar to each other morphologically,
but their megaspore ornamentations differ. These two
species are the only ones with dimorphic sporophylls
in the Oligomacrosporangiatae clade, and all the
remaining Asian/Pacific islands species of the genus
with dimorphic sporophylls are resolved as members
of the Heterostachys clade (XIII). Morphologically,
the distinguishing features of the S. pennata subclade
include dimorphic sporophylls, obovate dorsal leaves
and a swelling vein apex of ventral leaves. Additionally, the exospores of the megaspores of this subclade
are smooth (Fig. 3j, ‘B’), which is characteristic of this
subclade (Chang et al., 2002a; Liu et al., 2003). Our
study shows that the dimorphic sporophylls in Selaginella evolved at least twice independently, in the
S. pennata subclade and in the Heterostachys clade.
The Selaginella pervillei subclade
This subclade contains only Selaginella pervillei
Spring in our sampling. Plants of this species are erect
and have monomorphic stem leaves, and pubescent
stems and branches. These morphological features are
similar to those of members of the S. brunii subclade,
especially those of S. braunii. Our study shows, however, that they are not closely related, although they
are in the same larger clade (Fig. 2c). Hieronymus and
19
Sadebeck (1901) also placed S. braunii with the
S. pervillei group under their S. sect. Pleiomacrosporangiatae ser. Monostelicae. This group in their definition also includes three other species [S. eublepharis
AI. Br., S. fulcrata (Ham.) Spring and S. vogelii
Spring], which are probably part of this clade.
Megaspore surfaces of S. pervillei are sparsely papillate or tuberculate (Stefanovic et al., 1997; Korall and
Taylor, 2006) and microspore surfaces are tuberculate
(Stefanovic et al., 1997). It is similar to the S. delicatula subclade.
The Selaginella siamensis subclade
This subclade contains only Selaginella siamensis
Hieron. from Southeast Asia in our sampling. This
species is similar to the members of the S. willdenowii
subclade. However, this species occurs in drier habitats
than members of the S. willdenowii subclade. Walton
and Alston (1938) placed S. siamensis in a xerophytic
series and thought this species may be an intermediate
stage between taxa inhabiting xeromorphic versus
other habitats. This species has only one stele, its
megaspore surfaces are regularly verrucose (Fig. 3i),
and microspores have regular and twisted lamellate
ornamentation (Fig. 3u) (Liu et al., 2003). These morphological features are different from other members
of the Heterostachys clade.
The Selaginella willdenowii subclade
This subclade contains ca. six tropical Asian species
in our sampling. These species share the following features: (i) stems have three-banded vascular bundles [except that of S. uncinata]; (ii) plants are scandent and
usually 1 m long or longer; (iii) megaspore surfaces
have tuberculate–reticulate composite ornamentation
(Fig. 3g) (e.g. Minaki, 1984; Liu et al., 2003; Chu,
2006; Zhu et al., 2006; Korall and Taylor, 2006; Singh
et al., 2014; our own observations) and microspore
distal surfaces have long and twisted lamellate or
widely blunt–spiny ornamentation (Fig. 3s) (e.g. Liu
et al., 1989, 2003; Li et al., 2003); (iv) all leaves (dorsal
leaves, ventral leaves, axillary leaves and sporophylls)
are entire; and (v) the chromosome number is 2n = 18
[three species, S. uncinata, S. willdenowii (Desv. ex
Poir.) Baker and S. limbata Alston, have been examined] (Jermy et al., 1967; Takamiya, 1993). In addition, the leaves of some species (such as S. uncinata
and S. willdenowii) have iridescent schemochromic
tydall-blue colour (Setyawan, 2005). Two species of
this subclade, S. uncinata and S. willdenowii, have
been widely introduced to the Americas.
Based on the long stems, entire leaves, and similar
megaspores and microspores to those of the S.
willdenowii subclade (Zhang et al., 2005), the Hainan
20
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
endemic S. hainanensis X. C. Zhang & Noot. is probably a member of this subclade.
Clade XI—the Selaginella douglasii clade
This clade contains only the North American species
Selaginella douglasii (Hook. & Grev.) Spring in our
sampling. This species has a restricted geographical
distribution and is found only in California, Idaho,
Oregon, Washington and British Columbia (Jones,
1964; Valdespino, 1993). Hieronymus and Sadebeck
(1901) placed it in their S. douglasii group, one of their
28 groups under their S. sect. Pleiomacrosporangiatae
ser. Monostelicae, with three other species: S. delicatissima Linden ex A. Braun, S. saccharata A. Braun and
S. reflexa Underw. The last species is a member of
clade I, but the other two may not be members of this
clade. The S. douglasii clade was resolved as sister to
the Homostachys clade in our study (ML BS = 82%,
MP JK = 74%, PP = 0.97). This sister relationship is
supported by the short and creeping habit and verrucate ornamentation on megaspore surface (Tryon,
1949). However, this species has uniform strobili and
auriculate leaf bases, distinguishing it from members
of the Homostachys clade, but similar to members of
the Oligomacrosporangiatae clade.
Clade XII—the Homostachys clade
This clade approximates Selaginella subg. Homostachys Baker (1883), which was recognized by
Baker (1887), Warburg (1900) and Walton and Alston
(1938), but its members were included in either
S. subg. Homoeophyllae (Spring, 1850), S. sect. Dichotropae (Braun, 1857), S. subg. Heterophyllum
(Hieronymus and Sadebeck, 1901) or S. subg. Stachygynandrum (Jermy, 1986, 1990). Previous molecular
analyses based on sparse sampling included them in
S. subg. Stachygynandrum (Korall et al., 1999; Korall
and Kenrick, 2002). In our study, 29 accessions representing ca. 14 Asian and one Mediterranean species
(S. denticulata Spring) were sampled. The monophyly
of this clade was well established. Morphologically,
species of this clade share dimorphic leaves, creeping
stems and strobili non-resupinate (i.e. with dorsal
sporophylls smaller than ventral ones), except for
S. denticulata Spring and S. helvetica (L.) Link, which
have nearly isomorphic strobili. Based on the morphology of the strobili, the Homostachys clade can be
divided into two groups: (1) those with dimorphic strobili that are loose and non-resupinate; and (2) those
with strobili that are approximately monomorphic and
loose (S. denticulata and S. helvetica).
Although species of the Homostachys clade have
dimorphic sporophylls, they are obviously different
from other species with dimorphic sporophylls (e.g.
S. ciliaris and S. heterostachys from the Old World, and
S. flagellata and S. hartwegiana from the New World)
on the basis of their non-resupinate sporophylls and
loose strobili. Minaki (1984) studied the megaspore
morphology of four species of this clade (S. denticulata,
S. nipponica Franch. & Sav., S. helvetica, S. tamamontana Seriz.) and showed that they had similar tuberculate and/or vermiculate megaspore surfaces (Fig. 3e)
and wall structures. This sort of megaspore morphology
is not otherwise known in Selaginella. In fact members
of the Homostachys clade have obviously disconnected
laesurae at the pole of the megaspore (Fig. 3e, ‘A’),
which have long been ignored but earlier established by
several studies (e.g. Minaki, 1984; Liu et al., 1989, 2003;
Korall and Taylor, 2006).
Although Selaginella longistrobilina P.S. Wang, X.Y.
Wang & Li Bing Zhang (endemic to China) (Zhang
et al., 2012a) was not sampled in our analysis, it is probably a member of this clade based on its morphology.
Clade XIII—the Heterostachys clade
This clade contains species occurring mainly in Asia
and a small number of species in the Pacific islands,
and includes nearly all Asian species with resupinate
strobili (except S. bisulcata and S. pennata; see above).
Morphologically, members of this clade have dimorphic sporophylls and resupinate strobili. However,
none of the American species with dimorphic sporophylls belongs in the Heterostachys clade, which shows
that dimorphic sporophylls evolved independently in
Asian and American species. In our study, species of
the Heterostachys clade were resolved into two moderately supported subclades: the S. heterostachys subclade (from Asia) and the S. ciliaris subclade (from
Asia and the Pacific islands). The S. heterostachys subclade contains most Asian species with tuberculate and
verrucose megaspore surfaces (Fig. 3k) (e.g. Liu et al.,
1989, 2003, 2006; Zhou et al., 2012; Xia et al., 2013)
including the newly described S. daozhenensis Li Bing
Zhang, Q.W. Sun & Jun H. Zhao (Sun et al., 2015),
while the S. ciliaris subclade contains species of Asia
and the Pacific islands with megaspore surfaces that
are mainly finely reticulate (Fig. 3l).
In the S. ciliaris subclade, the Asian species were
resolved as sister to the Pacific island species (moderately supported: ML BS = 69%, MP JK = 82%, PP =
0.99). The megaspores of the six Asian species [S.
albociliata P.S. Wang, S. ciliaris (Retz.) Spring,
S. lutchensis Koidz., S. repanda (Desv. ex Poir.)
Spring, S. compta Spring, S. xipholepis Baker] and
Hawaiian species (S. arbuscula Spring) share an obviously open and fine reticulation (Fig. 3l) (except
S. compta) (e.g. Minaki, 1984; Liu et al., 2003; Liu
and Yan, 2004; Zhu et al., 2006; Singh et al., 2014).
This megaspore feature occurs only in this subclade.
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Based on the features of the megaspore morphology
(Singh et al., 2014) two Indian species, S. panchghaniana Dixit and S. proniflora (L.) Baker, are probably
members of the S. ciliaris subclade. Also, most other
Asian species with resupinate strobili probably fall
here.
Clade XIV—the Selaginella biformis clade
This clade contains only one Asian species, Selaginella biformis A. Braun ex Kuhn, in our sampling.
This species has two forms of habit: creeping flagelliform plants and erect plants. Its flagelliform plants are
glabrous and have no strobili, while its erect plants are
pubescent and often have strobili (Zhang et al., 2013;
our own observations). The flagelliform habit is also
present in some species of the S. pallescens clade
(XVI), such as S. porphyrospora A. Braun and S. flagellata Spring, and the Articulatae clade (VI), such as
S. sertata Spring, and these species all develop a flagelliform structure from the apex of the stem or branch
(Mickel and Smith, 2004). In contrast, the flagelliform
structure of S. biformis is developed from the base of
erect plants.
Selaginella biformis is similar to two species of the
S. involvens clade (XV), S. involvens (Sw.) Spring and
S. moellendorffii Hieron., in megaspore morphology
(Fig. 3m,o) and the morphology of leaves on the erect
stems. These species also share the chromosome number of 2n = 20 (Takamiya, 1993). Meanwhile, the separate ITS analysis resolved the clade XIV and clade XV
as sister clades, with moderate support (ML BS =
80%, MP JK = 84%) (tree not shown). The megaspores of S. biformis are reticulate (Fig. 3m) (Minaki,
1984; Liu et al., 1989) and the microspores are usually
sterile (our own observations).
Clade XV—the Selaginella involvens clade
This clade contains ca. four Asian species (Selaginella davidii Franch., S. gebaueriana Hand.-Mazz.,
S. involvens (Sw.) Spring and S. moellendorffii
Hieron.). Ventral leaves of the four species usually
have two light-coloured bands on the sides of veins
(Chu, 2006) and their megaspore surfaces are reticulate (Fig. 3n,o) (e.g. Minaki, 1984; Liu et al., 1989;
Sun et al., 2002; Xia et al., 2013). Selaginella involvens has a unique equatorial flange (Fig. 3n, ‘C’)
(Minaki, 1984; Liu et al., 1989; Xia et al., 2013).
Their microspores are baculate (S. davidii, S. gebaueriana and S. moellendorffii) or tuberculate and blunt–
spiny (S. involvens) (our own observations). This
clade was further resolved into two subclades: a
weakly supported S. involvens/S. moellendorffii subclade and a strongly supported S. davidii/S. gebaueriana subclade.
21
The Selaginella davidii subclade
This subclade contains two species in our sampling:
S. davidii and S. gebaueriana. Plants of this subclade
are creeping and their chromosome numbers are
unknown. The two species are difficult to distinguish
from each other and were treated as one species (e.g.
Alston, 1934; Zhang et al., 2013), two subspecies
(Zhang, 2004) or two species (Kung, 1988; Wang,
1990; Chu, 2006). In our phylogenetic analysis S. davidii was resolved as sister to S. gebaueriana with
strong support.
The Selaginella involvens subclade
This subclade contains two species in our sampling:
S. involvens and S. moellendorffii. Plants of this subclade are erect and have a chromosome number of
2n = 20 (Takamiya, 1993), and S. involvens also has a
varied number of 2n = 18–20 (Jermy et al., 1967). In
addition, S. involvens often grows on rocks and trees,
while S. moellendorffii can usually be found on the
ground. Because of their similar morphology, S. involvens and S. moellendorffii are often confused (Gu
et al., 2013), but the former has an equatorial flange
on its megaspore surfaces (Fig. 3n, ‘C’).
An equatorial flange similar to that of S. involvens is
also present in S. anceps A. Braun (Giorgi et al.,
1997), a member of our S. pallescens clade (XVI).
These two species also share erect plant habit and
microspore morphology, but the two were resolved in
different clades in the Stachygynandrum superclade,
suggesting that the equatorial flange may have evolved
twice independently.
Clades XVI–XIX—the OPHA clade (the S. oaxacana
clade, S. pallescens clade, S. hartwegiana clade and
S. anceps clade).
These four clades together (the OPHA clade) were
weakly supported (ML BS = 45%, MP JK < 50%,
PP = 0.74), and are composed of only New World species. Also these species share consistent megaspore
morphology, which are typically reticulate (Tryon,
1949; Hellwig, 1969; Korall and Taylor, 2006). They
are suberect, rarely creeping or erect, and have dimorphic leaves. These clades present various chromosome
numbers: 2n = 18 [S. apoda (L.) Fernald and S. simplex Baker] (Graustein, 1930; Marcon et al., 2005),
2n = 20 [S. erythropus Spring, S. flabellata (L.) Spring
and S. pulcherrima Liebm.] (Jermy et al., 1967). Meanwhile 2n = 20 (Jermy et al., 1967) and 22 (TschermakWoess and Dolezal-Janish, 1959) both occur in
S. pallescens (C. Presl) Spring. Species of these clades
with monomorphic or dimorphic sporophylls were
assigned to S. subg. Heterostachys and S. subg.
Stachygynandrum, respectively. The treatment was
22
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
adopted by Walton and Alston (1938) and Jermy
(1986). Our results, consistent with those of Korall
and Kenrick (2002), show that neither S. subg. Heterostachys nor S. subg. Stachygynandrum is monophyletic.
In addition to the species with dimorphic sporophylls sampled by Korall and Kenrick (2002), we sampled three species with dimorphic sporophylls:
S. flagellata, S. hartwegiana Spring and S. porphyrospora. Morphologically, these species are usually
small and creeping in habit and have resupinate strobili and dorsal sporophylls with sporophyll-pteryx
(Quansah and Thomas, 1985). The New World species
with dimorphic sporophylls are similar to the Asian
species in the Heterostachys clade (XIII), but they have
very different megaspore morphologies. Megaspore
surfaces of the species of clade XIII are tuberculate,
verrucose or papillate. According to Quansah and
Thomas (1985), about 14 species with dimorphic
sporophylls are distributed in West Africa and about
20 species in the Americas. Up to now, only seven
American species with dimorphic sporophylls have
been sampled in molecular studies, but no African species have been sampled. To understand the evolution
of dimorphic sporophylls well, more American and
African species need to be included in the phylogenetic
framework of Selaginella.
The relationships among 45 accessions representing
ca. 28 species in our sampling within the OPHA clade
are poorly resolved, but four strongly/weakly supported monophyletic clades are identified in our study:
the S. oaxacana clade (XVI), the S. pallescens clade
(XVII), the S. hartwegiana clade (XVIII) and the
S. anceps clade (XIX).
Clade XVI—the Selaginella oaxacana clade
This clade contains ca. three species in our sampling.
All species have reticulate megaspore surfaces
[S. martensii Spring: Giorgi et al., 1997; Korall and
Taylor, 2006; S. novae-hollandiae (Sw.) Spring: Korall
and Taylor, 2006; S. oaxacana Spring: Hellwig, 1969].
Although S. novae-hollandiae has dimorphic sporophylls, the megaspore morphology and our molecular
data all show that the three species in this clade are
closely related with one another. However, another
accession of S. novae-hollandiae from Ecuador has verrucate and spiny megaspore surfaces (Korall and Taylor, 2006). The two accessions were resolved as being
far away on our tree (Fig. 2e) and apparently represent different species (see below).
Clade XVII—the Selaginella pallescens clade
This clade contains ca. nine species in our sampling.
Morphologically, all species of the clade have
monomorphic sporophylls and reticulate megaspore
surfaces (Reeve, 1935; Tryon and Lugardon, 1991;
Korall and Taylor, 2006). However, members of this
clade present variable numbers of chromosomes
(S. apoda: 2n = 18; S. pallescens: 2n = 20, 22). Within
the clade, S. pallescens presents great variation in
habit (rosette to erect) and number of chromosomes
(2n = 20, 22). In our study, we added seven samples of
S. pallescens to the existing data, revealing a series of
complicated phylogenetic relationships. More morphological observations and cytological study are necessary to understand the species delimitations in this
complex.
Clade XVIII—the Selaginella hartwegiana clade
This clade contains species occurring in Central to
South America including Selaginella hartwegiana and
S. novae-hollandiae. They have stem nearly erect,
different from those species with dimorphic sporophylls from America that often have creeping stems.
They have dimorphic sterile leaves on the stem, different from those species with erect stems and monomorphic sporophyll species from America that have
monomorphic sterile leaves on the stem (Valdespino,
1993).
Clade XIX—the Selaginella anceps clade
This clade was weakly supported as monophyletic
(Fig. 2e) and is composed of only New World (South
& Central America) species. These species share typically reticulate megaspore surfaces (Tryon, 1949; Hellwig, 1969; Korall and Taylor, 2006). They are
suberect, rarely creeping or erect (if plants are erect,
main stems have monomorphic leaves), and have
dimorphic leaves and various chromosome numbers:
2n = 18 (S. simplex Baker) (Graustein, 1930; Marcon
et al., 2005), 2n = 20 [S. erythropus Spring and S.
flabellata (L.) Spring] (Jermy et al., 1967).
Clade XX—the Selaginella doederleinii clade
This clade was first found by Korall and Taylor
(2006). They observed megaspore morphology of five
species from Asia and Australia and found that their
megaspores have a surface with reticulum (Fig. 3p,q)
and a unique zona at the equator (Fig. 3p, ‘D’). In our
analysis, 18 accessions representing ca. 13 species across
China, Japan, Vietnam and Australia are sampled. Our
study further supports this clade as monophyletic. The
megaspore and microspore morphology of more species
have been observed, such as that of S. doederleinii (Liu
et al., 1989), S. frondosa Warb. (Liu et al., 2001),
S. commutata Alderw. (Zhao et al., 2006b; Fig. 3p,q),
and S. trichophylla K.H. Shing and S. scabrifolia Ching
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
& Chu H. Wang (our own observations). These results
all support the monophyly of this clade. Also, consistent
baculate microspores support the monophyly of the
clade (Zhao et al., 2006a; our own observations). Based
on the megaspore and microspore morphology (Liu
et al., 2001; our own observations), S. rolandi-principis
Alston, a species distributed Asia and with extremely
large ventral leaves (~7 mm), appears to be a member of
this clade.
Conclusions
Our study, based on combined plastid and nuclear
data from 394 accessions representing approximately
30% of the extant species of Selaginella, discovered six
deep-level clades and further identified 20 major evolutionary lineages within Selaginella. These clades/
lineages differ from one another in molecular, macromorphological, ecological and spore features, and/or
geographical distribution and deserve circumscription
as supraspecific entities within Selaginella (X.-M. Zhou
and L.-B. Zhang, unpublished data).
Acknowledgements
We thank Wei-Ming Chu and Alan R. Smith for
identification assistance, Pei-Shan Wang, and anonymous reviewers for helpful comments.
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Appendix
List of taxa sampled with information related to taxonomy, GenBank accession numbers, references and voucher information. Herbarium acronyms follow Index Herbariorum (Holmgren and
Holmgren, 1998).
Iso€
etes kersii Wanntorp, Kers 3130 (S), South Africa: rbcL
AF404498 (Rydin & Wikstr€
om, 2002); Iso€
etes kirkii A. Braun, Chinnock 447 (BM), New Zealand: rbcL AF404499 (Rydin & Wikstr€
om,
2002); Iso€
etes nuttallii A. Braun ex Engelm., Unknown, rbcL
DQ294246 (Schuettpelz & Hoot, 2006); Iso€
etes sinensis Palmer,
Unknown, rbcL GU564272 (X.Z. Kan, Z.C. Guo, and J. Wu,
unpublished); Iso€
etes taiwanensis De Vol., Unknown, rbcL
DQ294250 (Schuettpelz & Hoot, 2006).
Selaginella acanthonota Underw., Rothfels & Rushworth 4132
(DUKE), USA (North Carolina): rbcL KT161378, ITS KT161647;
Selaginella acanthostachys Baker, Korall 14a (S), Unknown: rbcL
AJ295884 (Korall and Kenrick, 2002); Selaginella albociliata P.S.
Wang, Zhang 5302 (CDBI), China (Guizhou): rbcL KT161379, ITS
KT161648; Selaginella alopecuroides Baker, Wikstr€
om & Wanntorp
nr146 (S), Borneo: rbcL AJ295875 (Korall and Kenrick, 2002); Selaginella amblyphylla Alston, (1) Zhang 5572 (CDBI), China (Guizhou): rbcL KT161380, ITS KT161651; (2) Gao & al. DJY04053
(CDBI), China (Sichuan): rbcL KT161381, ITS KT161649; (3) Gao
& al. DJY06425 (CDBI), China (Sichuan): rbcL KT161382, ITS
KT161650; Selaginella anceps (C. Presl) C. Presl, (1) Rothfels & al.
08-095 (DUKE), Costa Rica (Guanacaste): rbcL KT161383, ITS
KT161652; (2) Rothfels & al. 08-156 (DUKE), Costa Rica (Heredia):
rbcL KT161384, ITS KT161653; Selaginella apoda (L.) C. Morren,
(1) Murrell 6484 (S), Unknown: rbcL AJ010854 (Korall et al., 1999);
(2) Rothfels & al. 2884 (DUKE), USA (Virginia): rbcL KT161386,
ITS KT161655; (3) Rothfels & al. 2795 (DUKE), USA (Tennessee):
rbcL KT161385, ITS KT161654; Selaginella arbuscula Spring, (1)
Wood 13746 (PTBG), Hawaii (Maui, Kipahulu): rbcL KT161388,
ITS KT161657; (2) Wood 13447 (PTBG), Hawaii (Kauai, Wainiha):
rbcL KT161387, ITS KT161656; Selaginella arenicola Underw., Terrel 19 (MO), USA (Louisiana): rbcL AF419084 (Arrigo et al., 2013),
ITS AF419008 (Arrigo et al., 2013); Selaginella arizonica Maxon, (1)
Rothfels & al. 2539 (DUKE), USA (Arizona): rbcL KT161389, ITS
KT161658; (2) Eriksson 10/13 (S) Unknown: rbcL AJ010851 (Korall
et al., 1999); (3) Therrien and Windham s.n. (KANU), USA (Arizona): rbcL AF419078 (Arrigo et al., 2013), ITS AF419009 (Arrigo
et al., 2013); Selaginella arsenei Weath., (1) Rothfels & al. 2991
(DUKE), Mexico (Hidalgo): rbcL KT161390, ITS KT161659; (2)
Ferguson 14 (MO), Mexico (San Luis Potosı): rbcL AF419056 (Arrigo et al., 2013), ITS AF419029 (Arrigo et al., 2013); Selaginella
arthritica Alston (1) Rothfels & al. 2669 (DUKE), Costa Rica (Heredia): rbcL KT161391, ITS KT161661; (2) Rothfels & al. 08-185
(DUKE), Costa Rica (Heredia): rbcL KT161392, ITS KT161660;
Selaginella articulata (Kunze) Spring, Eriksson s.n. (S), Unknown:
rbcL AJ295894 (Korall and Kenrick, 2002); Selaginella asprella
Maxon, Therrien s.n. (KANU), USA (California): rbcL AF419064
(Arrigo et al., 2013), ITS AF419022 (Arrigo et al., 2013); Selaginella
cf. attirense, (1) Rothfels & al. 2657 (DUKE), Costa Rica (Guanacaste): rbcL KT161393; (2) Rothfels & al. 2611 (DUKE), Costa
Rica (San Jose): rbcL KT161422, ITS KT161662.
Selaginella balansae (A. Br.) Hieron., Gattefoss
e s.n. (S), Morocco
(Tamegdoult): rbcL AF419080 (Arrigo et al., 2013), ITS AF419005
(Arrigo et al., 2013); Selaginella biformis A. Braun ex Kuhn, (1)
Zhang & al. 6923 (CDBI, MO, VNMN, PYU), Vietnam (Ha Giang):
rbcL KT161398, ITS KT161668; (2) Zhang & al. 6729 (CDBI, MO,
VNMN, PYU), Vietnam (Bac Kan): rbcL KT161399, ITS
KT161667; (3) Jiang 316 (PYU, CDBI), China (Hainan): rbcL
KT161394, ITS KT161665; (4) He & Zhou 112 (PYU, CDBI), China
(Hainan): rbcL KT161395, ITS KT161663; (5) Zhang & al. 6687
(CDBI, MO, VNMN, PYU), Vietnam (Bac Kan): rbcL KT161400;
(6) Jiang 309 (PYU, CDBI), China (Hainan): rbcL KT161396, ITS
KT161664; (7) Zhang & al. 6685 (CDBI, MO, VNMN, PYU), Vietnam (Bac Kan): rbcL KT161397, ITS KT161666; (8) TNS777848
(TNS), Japan (Okinawa): rbcL AB574641 (Ebihara et al., 2010);
Selaginella bigelovii Underw., (1) Therrien s.n. (KANU), USA (California): rbcL AF419082 (Arrigo et al., 2013), ITS AF419004 (Arrigo
et al., 2013); (2) Rothfels & al. 2555 (DUKE), USA (California):
rbcL KT161401, ITS KT161669; (3) Rothfels & al. 2556 (DUKE),
USA (California): rbcL KT161402, ITS KT161670; (4) Rothfels & al.
2559 (DUKE), USA (California): rbcL KT161403, ITS KT161671;
Selaginella bisulcata Spring, (1) Chu & al. 31292 (PYU), China (Yunnan): rbcL KT161404, ITS KT161673; (2) Chu & al. 29311 (PYU),
China (Yunnan): rbcL KT161405, ITS KT161672; (3) Chu & al.
21737 (PYU), China (Yunnan): rbcL KT161408; (4) He & al. 71201
(PYU), China (Yunnan): rbcL KT161406, ITS KT161675; (5) He &
Zhou 122 (PYU, CDBI), China (Yunnan): rbcL KT161407, ITS
KT161674; Selaginella bodinieri Hieron., (1) Zhou & al. HGX11073
(CDBI), China (Sichuan): rbcL KT161412, ITS KT161676; (2) Ju &
Deng HGX13005 (CDBI), China (Sichuan): rbcL KT161413, ITS
KT161678; (3) Ju & Deng HGX12828 (CDBI), China (Sichuan): rbcL
KT161414, ITS KT161677; (4) Zhang 5193 (CDBI), China (Guizhou): rbcL KT161410, ITS KT161681; (5) Zhang 5913 (CDBI),
China (Guizhou): rbcL KT161409, ITS KT161680; (6) Zhang 5177
(CDBI), China (Guizhou): rbcL KT161411, ITS KT161679;
Selaginella bombycina Spring, (1) Rothfels & al. 08-204 (DUKE),
Costa Rica (Heredia): rbcL KT161415, ITS KT161682; (2) Korall 31
(S), Unknown: rbcL AJ010848 (Korall et al., 1999); Selaginella
boninensis Baker., (1) TNS766618 (TNS), Japan (Tokyo): rbcL
AB574642 (Ebihara et al., 2010); (2) Zhang & al. 6594 (CDBI, MO,
VNMN, PYU), Vietnam (Lang Son): rbcL KT161416, ITS
KT161868; (3) Zhang & al. 6587 (CDBI, MO, VNMN, PYU),
Vietnam (Lang Son): rbcL KT161417, ITS KT161683; Selaginella
braunii Baker, (1) Tiew 12 (CDBI), cult.: rbcL KT161421, ITS
KT161869; (2) Chu & al. s.n. (PYU), China (Yunnan): rbcL
KT161419, ITS KT161684; (3) Zhang 1332 (PYU, CDBI), China
(Hainan): rbcL KT161420, ITS KT161686; (4) Zhao 272 (CDBI),
China (Hubei): rbcL KT161418, ITS KT161685; Selaginella brooksii
Hieron., Wikstr€
om & Wanntorp nr141 (S), Borneo: rbcL AJ295876
(Korall and Kenrick, 2002).
Selaginella caffrorum (Milde) Hieron., Ventor and Vorster s.n.
(US), South Africa (Pretoria): rbcL AF419070 (Arrigo et al., 2013),
ITS AF419017 (Arrigo et al., 2013); Selaginella chaetoloma Alston,
(1) He & al. 29625 (PYU), China (Yunnan): rbcL KT161424, ITS
KT161689; (2) Chu & al. 29610 (PYU), China (Yunnan): rbcL
KT161425, ITS KT161688; (3) Chu & al. 24404 (PYU), China (Yunnan): rbcL KT161426, ITS KT161687; Selaginella chrysocaulos
(Hook. & Grev.) Spring, Xu & al. 2014-156 (CDBI), China
(Sichuan): rbcL KT161427, ITS KT161690; Selaginella ciliaris (Retz.)
Spring, (1) Jiang 310 (PYU, CDBI), China (Hainan): rbcL
KT161428, ITS KT161691; (2) Unknown, Peninsula Malaysia: rbcL
EU126658 (Y. Yi, Y. He, and B. Tan, unpublished); Selaginella cinerascens A.A. Eaton, (1) Rothfels & al. 2557 (DUKE), USA (California): rbcL KT161429, ITS KT161692; (2) Palmer 2651 (KANU),
USA (California): rbcL AF419063 (Arrigo et al., 2013), Therrien s.n.
(KANU), USA (California):ITS AF419027 (Arrigo et al., 2013); Selaginella commutata Alderw., Zhou 2441 (PYU), China (Guangxi):
rbcL KT161430, ITS KT161693. Selaginella compta Hand-Mazz. (1)
Zhou & al. DJY07488 (CDBI), China (Sichuan): rbcL KT161432,
ITS KT161694; (2) Zhou 012 (CDBI), China (Sichuan): rbcL
KT161434; (3) Luo 1378 (CDBI), China (Guizhou): rbcL KT161431,
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
ITS KT161695; (4) Sun 2001 (CDBI), China (Guizhou): rbcL
KT161433; (5) He H3384 (CTC) China (Sichuan): rbcL KT161435.
Selaginella daozhenensis Li Bing Zhang, Q.W. Sun & Jun H.
Zhao, Sun, Zhao & Pan 201435 (CDBI, GZTM), China (Guizhou):
rbcL KT161436; Selaginella davidii Franch., Chu & al. 23308 (PYU),
China (Beijing): rbcL KT161437, ITS KT161696; Selaginella decipiens Warb., (1) Zhang & al. 6764 (CDBI, MO, VNMN, PYU), Vietnam (Bac Kan): rbcL KT161438, ITS KT161698; (2) Zhang & al.
6761 (CDBI, MO, VNMN, PYU), Vietnam (Bac Kan): rbcL
KT161439, ITS KT161697; Selaginella deflexa Brack., Palmer 2651
(KANU), Hawaii (Honolulu): rbcL AF093253 (Arrigo et al., 2013),
ITS AF418999 (Arrigo et al., 2013); Selaginella delicatula (Desv. ex
Poir.) Alston, (1) Ju & Deng HGX12938 (CDBI), China (Sichuan):
rbcL KT161440, ITS KT161700; (2) Gao & al. HGX10734 (CDBI),
China (Sichuan): rbcL KT161441, ITS KT161699; Selaginella densa
Rydb., (1) Bj€
ork 25055 (UBC), Canada (British Columbia): rbcL
KT161442, ITS KT161701; (2) Therrien s.n. (KANU), USA (Colorado): rbcL AF419069 (Arrigo et al., 2013), ITS AF419036 (Arrigo
et al., 2013); Selaginella denticulata Spring, Korall & Eriksson 715
(S), Unknown: rbcL AJ010853 (Korall et al., 1999); Selaginella diffusa (C. Presl) Spring, (1) Rothfels & al. 08-087 (DUKE), Costa Rica
(Puntarenas): rbcL KT161443, ITS KT161702; (2) Korall 33 (S),
cult.: rbcL AJ010852 (Korall et al., 1999); Selaginella digitata Spring,
Rakotondrainibe 3255 (P), Madagascar (d’Andohahela): rbcL
AJ295895 (Korall and Kenrick, 2002); Selaginella doederleinii
Hieron., (1) Jiang 313 (PYU, CDBI), China (Hainan): rbcL
KT161444; (2) TNS763070 (TNS), Japan (Kagoshima): rbcL
AB574643 (Ebihara et al., 2010); (3) Zhang & al. 6447 (CDBI, MO,
VNMN, PYU), Vietnam (Vinh Phuc): rbcL KT161445; Selaginella
douglasii (Hook. & Grev.) Spring, (1) Unknown, rbcL AF419049
(J.P. Therrien and C.H. Haufler, unpublished); (2) Rothfels & al.
3863 (DUKE), USA (Oregon): rbcL KT161446, ITS KT161870; Selaginella dregei (C. Presl) Hieron., Faden 9-85 (US), Kenya (Isiolo):
rbcL AF419055 (Arrigo et al., 2013), ITS AF419015 (Arrigo et al.,
2013); Selaginella drepanophylla Alston, (1) Zhang 5117 (CDBI),
China (Guizhou): rbcL KT161447, ITS KT161703; (2) Zhang 5862
(CDBI), China (Guizhou): rbcL KT161448.
Selaginella echinata Baker, Fosberg 52393 (US), Madagascar (Fianarantsoa): rbcL AF419071 (Arrigo et al., 2013), ITS AF419021 (Arrigo et al., 2013); Selaginella effusa var. dulongjiangensis W. M. Chu,
Chu & al. 31299 (PYU), China (Yunnan): rbcL KT161449, ITS
KT161704; Selaginella effusa Alston, (1) Zhang 5438 (CDBI), China
(Guizhou): rbcL KT161450, ITS KT161706; (2) Dong 2470 (PYU),
China (Guangdong): rbcL KT161453, ITS KT161705; (3) Zhang
5442 (CDBI), China (Guizhou): rbcL KT161451, ITS KT161707; (4)
Wang 20051 (CDBI), China (Guizhou): rbcL KT161452, ITS
KT161708; Selaginella eremophila Maxon, (1) Therrien s.n. (KANU),
USA (California): rbcL AF419079 (Arrigo et al., 2013), ITS
AF419010 (Arrigo et al., 2013); (2) Rothfels & al. 2549 (DUKE),
USA (California): rbcL KT161454, ITS KT161710; (3) Rothfels & al.
2561 (DUKE), USA (California): rbcL KT161455, ITS KT161709;
Selaginella erythropus (Mart.) Spring, Korall 1998:2 (S), cult.: rbcL
AJ295877 (Korall and Kenrick, 2002); Selaginella eurynota A.
Braun, Rothfels & al. 08-183 (DUKE), Costa Rica (Heredia): rbcL
KT161456; Selaginella exaltata (Kunze) Spring, Korall 1996:1 (S),
Unknown: rbcL AJ010849 (Korall et al., 1999); Selaginella extensa
Underw., McVaugh 11829 (US), Mexico (Jalisco): rbcL AF419085
(Arrigo et al., 2013), ITS AF419026 (Arrigo et al., 2013).
Selaginella firmuloides Warb., Wikstr€
om 233 (S), New Caledonia:
rbcL AJ295870 (Korall and Kenrick, 2002); Selaginella flabellata (L.)
Spring, Webster & al. 9553 (S), Grenada (Lesser Antilles): rbcL
AJ295885 (Korall and Kenrick, 2002); Selaginella flagellata Spring,
(1) Rothfels & al. 08-157 (DUKE), Costa Rica (Heredia): rbcL
KT161457, ITS KT161711; (2) Ortega & al. 3090 (BM), Unknown:
rbcL AJ295866 (Korall and Kenrick, 2002); Selaginella flexuosa
Spring, Rothfels & Sigel 3627 (DUKE), Ecuador (Zamora-Chinchipe): rbcL KT161458, ITS KT161712; Selaginella fragilis A. Braun,
27
Korall 1996:3 (S), Unknown: rbcL AJ295872 (Korall and Kenrick,
2002); Selaginella frondosa Warb., (1) Wikstr€
om & Wanntorp nr126
(S), Unknown: rbcL AJ295874 (Korall and Kenrick, 2002); (2) Chu
& al. 29274A (PYU), China (Yunnan): rbcL KT161459, ITS
KT161713.
Selaginella gebaueriana Hand.-Mazz., (1) Deng 102 (CDBI), China
(Guizhou): rbcL KT161460, ITS KT161716; (2) Chu & al.089
(PYU), China (Yunnan): rbcL KT161463, ITS KT161715; (3) Zhang
5804 (CDBI), China (Guizhou): rbcL KT161461, ITS KT161718; (4)
Shui 40568 (PYU), China (Yunnan): rbcL KT161464, ITS
KT161719; (5) Zhang 5735 (CDBI), China (Guizhou): rbcL
KT161462, ITS KT161717; (6) Chu & He 29611 (PYU), China (Yunnan): rbcL KT161465, ITS KT161714; Selaginella gracillima
(Kuntze) Alston, Nordenstam & Anderberg 1124 (S), Australia (Tasmania): rbcL AJ010844 (Korall et al., 1999); Selaginella grisea
Alston, Unknown, rbcL AF419072 (Arrigo et al., 2013).
Selaginella haematodes (Kunze) Spring, Korall 1996:15b (S),
Unknown: rbcL AJ010846 (Korall et al., 1999); Selaginella hansenii
Hieron., Weber 15108 (COLO), USA (California): rbcL AF419057
(Arrigo et al., 2013), ITS AF419033 (Arrigo et al., 2013); Selaginella
harrisii Underw. & Hieron., (1) Beck 1124 (DUKE), Mexico (San
Luis Potosı): rbcL KT161466, ITS KT161720; (2) Beck 1112
(DUKE), Mexico (Hidalgo): rbcL KT161467; Selaginella hartwegiana
Spring, Rothfels & al. 3605 (DUKE), Ecuador (Loja): rbcL
KT161468, ITS KT161721; Selaginella helferi Warb., (1) He & Jiang
302 (PYU, CDBI), China (Yunnan): rbcL KT161469, ITS
KT161722; (2) Zhang & al. 6919 (CDBI, MO, VNMN, PYU), Vietnam (Ha Giang): rbcL KT161471, ITS KT161724; (3) He & Jiang
406 (PYU, CDBI), China (Yunnan): rbcL KT161470, ITS
KT161723; Selaginella helioclada Alston ex Alston, Rakotondrainibe
3262 (P), Madagascar (d’Andohahela): rbcL AJ295896 (Korall and
Kenrick, 2002); Selaginella helvetica (L.) Link, (1) Klackenberg
820617-12 (S), Unknown: rbcL AJ295891 (Korall and Kenrick,
2002); (2) Zhou 093 (CDBI), China (Sichuan): rbcL KT161472, ITS
KT161871; (3) TNS765114 (TNS), Japan (Akita): rbcL AB574644
(Ebihara et al., 2010); Selaginella heterostachys Baker, (1) Jiang 317
(PYU, CDBI), China (Hainan): rbcL KT161478, ITS KT161732; (2)
Jiang 315 (PYU, CDBI), China (Hainan): rbcL KT161479; (3)
Zhang 5455 (CDBI), China (Guizhou): rbcL KT161473, ITS
KT161733; (4) Zhang & al. 6641 (CDBI, MO, VNMN, PYU), Vietnam (Thai Nguyen to Kim Hy): rbcL KT161483, ITS KT161731; (5)
Zhang & al. 6608 (CDBI, MO, VNMN, PYU), Vietnam (Lang Son):
rbcL KT161481, ITS KT161729; (6) Zhang 5550 (CDBI), China
(Guizhou): rbcL KT161474, ITS KT161727; (7) Zhang & al. 6617
(CDBI, MO, VNMN, PYU), Vietnam (Lang Son): rbcL KT161482,
ITS KT161730; (8) Zhang 5655 (CDBI), China (Guizhou): rbcL
KT161475, ITS KT161728; (9) TNS769193 (TNS), Japan (Mie):
rbcL AB574645 (Ebihara et al., 2010); (10) Gao & al. DJY05340
(CDBI), China (Sichuan): rbcL KT161477, ITS KT161725; (11)
Zhang 5180 (CDBI), China (Guizhou): rbcL KT161476, ITS
KT161726; (12) Zhang & al. 6390 (CDBI, MO, VNMN, PYU), Vietnam (Hoa Binh): rbcL KT161480, ITS KT161734; Selaginella hoffmannii Hieron., (1) Rothfels & al. 08-088 (DUKE), Costa Rica
(Puntarenas): rbcL KT161485, ITS KT161735; (2) Rothfels & al. 08138 (DUKE), Costa Rica (Puntarenas): rbcL KT161484, ITS
KT161736.
Selaginella imbricata (Forssk.) Spring ex Decne., (1) Rothfels & al.
4275 (DUKE), Oman (Dhofar, Governorate) rbcL KT161486, ITS
KT161737; (2) Parris & Croxall 83/19 (P), Unknown: rbcL AJ295897
(Korall and Kenrick, 2002); Selaginella indica (Milde) R.M. Tryon, (1)
Saldanha 15198 (US), India (Hassan): rbcL AF419052 (Arrigo et al.,
2013), ITS AF419020 (Arrigo et al., 2013); (2) Tiew 01 (CDBI), cult.:
rbcL KT161488, ITS KT161739; (3) He & al. 29779 (PYU), China
(Yunnan): rbcL KT161487, ITS KT161738; Selaginella intermedia
Spring Unknown, Peninsula Malaysia: rbcL EU086853 (Y. Yi, Y. He,
and B. Tan, unpublished); Selaginella involvens (Sw.) Spring (1) Tiew
13 (CDBI), cult.: rbcL KT161492, ITS KT161743; (2) Zhang & al.
28
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
6576 (CDBI, MO, VNMN, PYU), Vietnam (Phu Tho): rbcL
KT161493, ITS KT161742; (3) He & Zhou 103 (PYU, CDBI), China
(Yunnan): rbcL KT161491; (4) Zhou & al. DJY03558 (CDBI), China
(Sichuan): rbcL KT161489, ITS KT161740; (5) TNS762549 (TNS),
Japan (Kagoshima): rbcL AB574646 (Ebihara et al., 2010); (6) He &
Zhou 114 (PYU, CDBI), China (Yunnan): rbcL KT161490, ITS
KT161741.Selaginella jugorum Hand.-Mazz., Meili Exped. 25060
(PYU), China (Yunnan): rbcL KT161494.
Selaginella kanehirae Alston, (1) Wood 13568 (PTBG), F.S.M.
(Caroline Is., Pohnpei): rbcL KT161495, ITS KT161745; (2) Wood
13567 (PTBG), F.S.M. (Caroline Is., Pohnpei): rbcL KT161496, ITS
KT161744; Selaginella kerstingii Hieron., Korall 1998:8 (S), cult.:
rbcL AJ295881 (Korall and Kenrick, 2002); Selaginella kraussiana
(Kunze) A. Braun, (1) Chu & al. s.n. (PYU), cult.,: rbcL KT161497;
(2) Zhou 062 (CDBI), cult.,: rbcL KT161498, ITS KT161746; (3)
Korall 1997:30 (S), cult.: rbcL AJ010845 (Korall et al., 1999);
Selaginella kunzeana A. Braun, Rothfels & al. 08-096 (DUKE), Costa
Rica (Puntarenas): rbcL KT161499, ITS KT161747; Selaginella
kurzii Baker, (1) He & Jiang 405 (PYU, CDBI), China (Yunnan):
rbcL KT161500, ITS KT161749; (2) He & Zhou 117 (PYU, CDBI),
China (Yunnan): rbcL KT161501, ITS KT161748.
Selaginella labordei Hieron. ex Christ, (1) Zhou & al. DJY03560
(CDBI), China (Sichuan): rbcL KT161504; (2) Gao & al. DJY03894
(CDBI), China (Sichuan): rbcL KT161502, ITS KT161750; (3) Gao
& al. DJY04311 (CDBI), China (Sichuan): rbcL KT161503, ITS
KT161751; (4) Zhou 008 (CDBI), China (Sichuan): rbcL KT161505;
Selaginella landii Greenm. & N. Pfeiff., (1) Rothfels & al. 3111
(DUKE), Mexico (Jalisco): rbcL KT161506, ITS KT161752; (2)
Matuda 8-52 (US), Mexico (Moreles): rbcL AF419086 (Arrigo et al.,
2013), ITS AF419012 (Arrigo et al., 2013); Selaginella laxistrobila
K.H. Shing, (1) He & al. 29624 (PYU), China (Yunnan): rbcL
KT161507, ITS KT161754; (2) He & al. 81841 (PYU), China (Yunnan): rbcL KT161508, ITS KT161755; (3) Chu & al. 24449 (PYU),
China (Yunnan): rbcL KT161509, ITS KT161753; Selaginella lepidophylla (Hook. & Grev.) Spring, (1) Therrien 1996:s.n. (KANU),
Unknown: rbcL AF093254 (Arrigo et al., 2013); (2) Worthington s.n.
(US), USA (Texas): rbcL AF419051 (Arrigo et al., 2013); Selaginella
leptophylla Baker, (1) He & Zhou 101 (PYU, CDBI), China (Yunnan): rbcL KT161514, ITS KT161757; (2) Zhou 011 (CDBI), China
(Sichuan): rbcL KT161512, ITS KT161760; (3) Zhou & al.
DJY05380 (CDBI), China (Sichuan): rbcL KT161513, ITS
KT161756; (4) Zhang 5853 (CDBI), China (Guizhou): rbcL
KT161510, ITS KT161759; (5) Zhang 5199 (CDBI), China (Guizhou): rbcL KT161511, ITS KT161758; Selaginella leucobryoides
Maxon, (1) Rothfels & al. 2565 (DUKE), USA (California): rbcL
KT161515, ITS KT161761; (2) Windham 97-055 (DUKE), USA
(Arizona): rbcL AF419068 (Arrigo et al., 2013), ITS AF419023 (Arrigo et al., 2013); Selaginella limbata Alston, TNS764147 (TNS),
Japan (Kagoshima): rbcL AB574647 (Ebihara et al., 2010); Selaginella lingulata Spring, Korall 1996:4 (S), Unknown: rbcL
AJ295882 (Korall and Kenrick, 2002); Selaginella longiaristata
Hieron., Wikstr€
om & Wanntorp nr139(S), Unknown: rbcL
AJ295873 (Korall and Kenrick, 2002); Selaginella longipinna Warb.,
Lundberg s.n. (S), Unknown: rbcL AJ295860 (Korall and Kenrick,
2002); Selaginella lutchuensis Koidz., TNS759343 (TNS), Japan (Okinawa): rbcL AB574648 (Ebihara et al., 2010); Selaginella lyallii
(Hook. & Grev.) Spring, Malcomber & al. 1383 (P), Madagascar
(Fianarantsoa): rbcL AJ295898 (Korall and Kenrick, 2002).
Selaginella mairei H. Lev., (1) He & al. 81906 (PYU), China
(Yunnan): rbcL KT161517, ITS KT161765; (2) He & Zhou 118
(PYU, CDBI), China (Yunnan): rbcL KT161519, ITS KT161764; (3)
Chu & He s.n. (PYU), China (Yunnan): rbcL KT161518, ITS
KT161762; (4) He & Zhao 3348 (CTC) China (Sichuan): rbcL
KT161516, ITS KT161763; Selaginella martensii Spring, (1) Korall
1998:3 (S), cult.: rbcL AJ295878 (Korall and Kenrick, 2002); (2)
Beck 1222 (DUKE), Mexico (Oaxaca): rbcL KT161520; Selaginella
matsuensis C. M. Kuo, Knapp 2642 (HAST), China (Taiwan): rbcL
KT161521, ITS KT161766; Selaginella mayeri Hieron., Unknown,
Peninsula Malaysia: rbcL EU197125 (Y. Yi, Y. He, and B. Tan,
unpublished); Selaginella megaphylla Baker, (1) Zhang & al. 6330
(CDBI, MO, VNMN, PYU), Vietnam (Hoa Binh): rbcL KT161527,
ITS KT161771; (2) Zhang & al. 6935 (CDBI, MO, VNMN, PYU),
Vietnam (Ha Giang): rbcL KT161526, ITS KT161772; (3) Zhang
4958 (CDBI), China (Guizhou): rbcL KT161522, ITS KT161768; (4)
Zhang 5185 (CDBI), China (Guizhou): rbcL KT161523, ITS
KT161769; (5) Zhang 5200 (CDBI), China (Guizhou): rbcL
KT161524, ITS KT161770; (6) Chu & al. 8226 (PYU), China (Yunnan): rbcL KT161525, ITS KT161767; Selaginella microphylla
(Kunth) Spring, Rothfels & al. 3586 (DUKE), Ecuador (Carchi):
rbcL KT161528, ITS KT161773; Selaginella moellendorffii Hieron.,
(1) Ju & Deng HGX12307 (CDBI), China (Sichuan): rbcL
KT161529, ITS KT161775; (2) Ju & Deng HGX12475 (CDBI), China
(Sichuan): rbcL KT161530, ITS KT161776; (3) Ju & Deng
HGX12295 (CDBI), China (Sichuan): rbcL KT161531, ITS
KT161774; (4) Rothfels & al. 08-090 (DUKE), introduced to Costa
Rica (Puntarenas): rbcL KT161533, ITS KT161777; (5) Tiew 14
(CDBI), cult.: rbcL KT161532, ITS KT161778; Selaginella monospora Spring, (1) Zhang & al. 6430 (CDBI, MO, VNMN, PYU),
Vietnam (Vinh Phuc): rbcL KT161537, ITS KT161782; (2) Chu & al.
31293 (PYU), China (Yunnan): rbcL KT161535, ITS KT161780; (3)
Jiao s.n. (PYU), China (Yunnan): rbcL KT161536, ITS KT161781;
Selaginella cf. monospora, Chu & al. 14863 (PYU), China (Yunnan):
rbcL KT161534, ITS KT161779; Selaginella moratii Rauh & W.
Hagemann, Mabberley 913 (P), Madagascar (Fianarantsoa): rbcL
AJ295899 (Korall and Kenrick, 2002); Selaginella moritziana Spring
ex Klotzsch, Korall 1996:12 (S), Unknown: rbcL AJ010856 (Korall
et al., 1999); Selaginella mutica D.C.Eaton, Therrien s.n. (KANU),
USA (Colorado): rbcL AF419058 (Arrigo et al., 2013), ITS
AF419025 (Arrigo et al., 2013); Selaginella mutica var. limitanea
Weath., (1) Rothfels & al. 2505 (DUKE), USA (New Mexico): rbcL
KT161538, ITS KT161872; (2) Rothfels & al. 2495 (DUKE), USA
(Texas): rbcL KT161539; Selaginella myosurus (Sw.) Alston, G€
osta
Lindeberg s.n. (S), Unknown: rbcL AJ295863 (Korall and Kenrick,
2002).
Selaginella 9neomexicana Maxon, (1) Rothfels & al. 2506
(DUKE), USA (New Mexico): rbcL KT161642, ITS KT161883; (2)
Beck & al. 1055 (DUKE), USA (New Mexico): rbcL KT161643, ITS
KT161882; Selaginella nipponica Franch. & Sav., (1) Zhou & al.
DJY05391 (CDBI), China (Sichuan): rbcL KT161540, ITS
KT161873; (2) Zhou & al. DJY05495 (CDBI), China (Sichuan):
rbcL KT161541, ITS KT161783; (3) Zhou & al. DJY07479 (CDBI),
China (Sichuan): rbcL KT161542, ITS KT161784; (4) Knapp 2650
(HAST), China (Taiwan): rbcL KT161544, ITS KT161785; (5) Zhou
098 (CDBI), China (Sichuan): rbcL KT161543, ITS KT161786; (6)
TNS738139 (TNS), Japan (Tokyo): rbcL AB574649 (Ebihara et al.,
2010); Selaginella nivea Alston, Fosberg 52583 (US), Madagascar
(Tulear): rbcL AF419073 (Arrigo et al., 2013), ITS AF419014
(Arrigo et al., 2013); Selaginella njamnjamensis Hieron., Faden 34485 (MO), Kenya (Kwale): rbcL AF419074 (Arrigo et al., 2013), ITS
AF419016 (Arrigo et al., 2013); Selaginella nothohybrida Valdespino,
Rothfels & al. 3069 (DUKE), Mexico (San Luis Potosı): rbcL
KT161545; Selaginella novae-hollandiae (Sw.) Spring, (1) Ortega &
Smith 3136 (BM), Venezuela: rbcL AJ295865 (Korall and Kenrick,
2002); (2) Korall 1996:8 (S), Ecuador: rbcL AJ295883 (Korall and
Kenrick, 2002); Selaginella nummularifolia Ching, Ludlow & al. 4233
(PE), China (Xizang): rbcL KT161546, ITS KT161787.
Selaginella oaxacana Spring, (1) Rothfels & al. 3345 (DUKE),
Mexico (Oaxaca): rbcL KT161548, ITS KT161789; (2) Rothfels &
al. 3344 (DUKE), Mexico (Oaxaca): rbcL KT161549, ITS
KT161788; (3) Rothfels & al. 08-186 (DUKE), Costa Rica (Heredia):
rbcL KT161547; Selaginella oregana D.C. Eaton, Therrien and Bostwick s.n. (KANU), USA (Washington): rbcL AF419066 (Arrigo
et al., 2013), ITS AF419030 (Arrigo et al., 2013).
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
Selaginella pallescens (C. Presl) Spring, (1) Korall 1998:7 (S), cult.:
rbcL AJ295858 (Korall and Kenrick, 2002); (2) Unknown: rbcL
AJ295859 (Korall and Kenrick, 2002); (3) Unknown, rbcL
AF419050 (J.P. Therrien and C.H. Haufler, unpublished); (4) Rothfels & al. 2701 (DUKE), Costa Rica (San Jose): rbcL KT161553,
ITS KT161794; (5) Rothfels & al. 2644 (DUKE), Costa Rica (Guanacaste): rbcL KT161550, ITS KT161792; (6) Beck 1120 (DUKE),
Mexico (Hidalgo): rbcL KT161555, ITS KT161790; (7) Rothfels &
al. 2656 (DUKE), Costa Rica (Guanacaste): rbcL KT161551, ITS
KT161793; (8) Rothfels & al. 3279 (DUKE), Mexico (Oaxaca): rbcL
KT161554, ITS KT161795; (9) Grusz & al. 08-002 (DUKE), Costa
Rica (Heredia): rbcL KT161552, ITS KT161791; Selaginella pallidissima Spring, He & Zhao 3386 (CTC) China (Sichuan): rbcL
KT161556, ITS KT161796; Selaginella pennata (D. Don) Spring (1)
He & Jiang 404 (PYU, CDBI), China (Yunnan): rbcL KT161558,
ITS KT161798; (2) Chu & al. 24587 (PYU), China (Yunnan): rbcL
KT161557, ITS KT161797; Selaginella peruviana (Milde) Hieron., (1)
Rothfels & al. 3280 (MEXU) Mexico (Oaxaca): rbcL KT161559, ITS
KT161799; (2) Therrien and Bostwick s.n. (KANU), USA (Texas):
rbcL AF419087 (Arrigo et al., 2013), ITS AF419013 (Arrigo et al.,
2013); Selaginella pervillei Spring, Rakotondrainibe 3355 (P), Madagascar (d’Antsiranana): rbcL AJ295901 (Korall and Kenrick, 2002);
Selaginella phillipsiana (Hieron.) Alston, Faden 74-935 (F), Kenya
(Isiolo): rbcL AF419061 (Arrigo et al., 2013), ITS AF419019 (Arrigo
et al., 2013); Selaginella picta A. Braun ex Baker, (1) Zhang & al.
6525 (CDBI, MO, VNMN, PYU), Vietnam (Phu Tho): rbcL
KT161562, ITS KT161802; (2) Chu & al. 21911 (PYU), China (Yunnan): rbcL KT161560, ITS KT161800; (3) He & Zhou 110 (PYU,
CDBI), China (Yunnan): rbcL KT161561, ITS KT161801;
Selaginella pilifera A. Braun, Pringle 13959 (S), Unknown: rbcL
AJ295862 (Korall and Kenrick, 2002); Selaginella plana (Desv. ex
Poir.) Hieron., (1) Korall 1998:5 (S), cult.: rbcL AJ295880 (Korall
and Kenrick, 2002); (2) Tiew 08 (CDBI), cult.:rbcL KT161563, ITS
KT161803; Selaginella polymorpha Badre, Rakotondrainibe 3533 (P),
Madagascar (d’Antsiranana): rbcL AJ295900 (Korall and Kenrick,
2002); Selaginella porphyrospora A. Braun, Rothfels & al. 08-001
(DUKE), Costa Rica (Heredia): rbcL KT161564, ITS KT161804; Selaginella prostrata (H.S. Kung) Li Bing Zhang, (1) Gao & al.
DJY03769 (CDBI), China (Sichuan): rbcL KT161566; (2) Zhu &
Zhou DJY03956 (CDBI), China (Sichuan): rbcL KT161565, ITS
KT161874; Selaginella pseudonipponica Tagawa, (1) Knapp 3375,
Knapp’s private herbarium, China (Taiwan): rbcL KT161567, ITS
KT161806; (2) Knapp 3381 (P), China (Taiwan): rbcL KT161569,
ITS KT161808; (3) Knapp 3291 (P), China (Taiwan): rbcL
KT161570, ITS KT161805; (4) Moore 17161 (PYU), China (Taiwan): rbcL KT161574; (5) Knapp 3378 (P), China (Taiwan): rbcL
KT161571, ITS KT161876; (6) Knapp 3377, Knapp’s private herbarium, China (Taiwan): rbcL KT161568, ITS KT161875; (7) Knapp
3379 (P), China (Taiwan): rbcL KT161572, ITS KT161807; (8)
Knapp 3380 (P), China (Taiwan): rbcL KT161573; Selaginella
pseudopaleifera Hand.-Mazz., Zhang & al. 6324 (CDBI, MO,
VNMN, PYU), Vietnam (Hoa Binh): rbcL KT161575, ITS
KT161809; Selaginella pulcherrima Liebm., Korall 1997:32 (S), cult.:
rbcL AJ010847 (Korall et al., 1999); Selaginella pulvinata (Hook. &
Grev.) Maxim., (1) Zhou 066 (CDBI), China (Sichuan): rbcL
KT161576, ITS KT161810; (2) Zhou 501 (PYU, CDBI), China
(Xizang): rbcL KT161577, ITS KT161811; Selaginella pygmaea
Alston, Esterhuysen 34078a (BOL) Unknown: rbcL AJ295892
(Korall and Kenrick, 2002).
Selaginella radiata Baker, Cremers 10068 (BM), French guiana:
rbcL AJ295867 (Korall and Kenrick, 2002); Selaginella reflexa
Underw., Beck 1126 (DUKE), Mexico (San Luis Potosı): rbcL
KT161578, ITS KT161812; Selaginella remotifolia Spring, (1) Hsu
5194 (S), Unknown: rbcL AJ295864 (Korall and Kenrick, 2002); (2)
TNS765133 (TNS), Japan (Shizuoka): rbcL AB574650 (Ebihara
et al., 2010); (3) Ju & Deng HGX13191 (CDBI), China (Sichuan):
rbcL KT161579, ITS KT161813; (4) Zhou 005 (PYU, CDBI), China
29
(Yunnan): rbcL KT161580, ITS KT161814; Selaginella repanda
(Desv. ex Poir.) Spring, (1) He & Jiang 405-1 (CDBI), China (Yunnan): rbcL KT161584; (2) He & Zhou 115 (PYU, CDBI), China
(Yunnan): rbcL KT161582, ITS KT161815; (3) He & al. s.n. (PYU),
China (Yunnan): rbcL KT161581, ITS KT161817; (4) He & Zhou
119 (PYU, CDBI), China (Yunnan): rbcL KT161583, ITS
KT161816; Selaginella roxburghii (Hook. & Grev.) Spring,
Unknown, Peninsula Malaysia: rbcL EU140945 (Y. Yi, Y. He, and
B. Tan, unpublished); Selaginella rupestris (L.) Spring, (1) Rothfels &
Rushworth 4172 (DUKE), USA (North Carolina): rbcL KT161586,
ITS KT161819; (2) Rothfels & al. 4493 (UBC), Canada (Ontario):
rbcL KT161585, ITS KT161818; (3) Therrien 1996:356 (KANU),
USA (Illinois): rbcL AF093255 (Korall et al., 1999), ITS AF419038
(Arrigo et al., 2013); Selaginella rupincola Underw., (1) Rothfels &
al. 2508 (DUKE), USA (New Mexico): rbcL KT161587, ITS
KT161820; (2) Therrien and Windham s.n. (KANU), USA (Arizona):
rbcL AF419083 (Arrigo et al., 2013), ITS AF419003 (Arrigo et al.,
2013); (3) s.n. (S), S. USA: rbcL AJ010850 (Korall et al., 1999).
Selaginella sanguinolenta (L.) Spring, (1) Zhou 003 (PYU, CDBI),
China (Yunnan): rbcL KT161591; (2) He & Zhao 3514 (CTC) China
(Sichuan): rbcL KT161589, ITS KT161821; (3) He & Zhao 3399
(CTC) China (Sichuan): rbcL KT161590, ITS KT161822; (4) Zhou
092 (CDBI), China (Sichuan): rbcL KT161588, ITS KT161823; (5)
Unknown, rbcL EU197124 (Y. Yi, Y. He, and B. Tan, unpublished);
Selaginella sartorii Hieron., (1) Fosberg 22205 (US), Colombia (Boyoca): rbcL AF419054 (Arrigo et al., 2013), ITS AF419039 (Arrigo
et al., 2013); (2) Rothfels & al. 3067 (DUKE), Mexico (San Luis
Potosı): rbcL KT161592, ITS KT161877; Selaginella scabrifolia
Ching & Chu H. Wang, He & Zhou 109 (PYU, CDBI), China (Hainan): rbcL KT161593, ITS KT161824; Selaginella scopulorum
Maxon, (1) Rothfels & al. 4507 (UBC), USA (Washington): rbcL
KT161595, ITS KT161825; (2) Rothfels & al. 4473 (UBC), Canada
(British Columbia): rbcL KT161594, ITS KT161826; Selaginella
selaginoides (L.) P. Beauv. ex Mart. & Schrank, (1) TNS766485
(TNS), Japan (Nagano): rbcL AB574651 (Ebihara et al., 2010); (2)
Therrien s.n. (KANU), Canada (Ontario): rbcL AF419048 (Arrigo
et al., 2013), ITS AF419000; (3) Eriksson s.n. (S), Unknown: rbcL
Y07940 (Wikstr€
om and Kenrick, 1997); Selaginella sellowii Hieron.,
(1) Rothfels & al. 3604 (DUKE), Ecuador (Carchi): rbcL KT161596,
ITS KT161827; (2) Acevedo 4571 (US), Bolivia (Florıda): rbcL
AF419053 (Arrigo et al., 2013), ITS AF419028 (Arrigo et al., 2013);
(3) Wanntorp & Holmgren 557 (S), Unknown: rbcL AJ295889 (Korall and Kenrick, 2002); Selaginella sericea A. Braun, (1) Korall
1996:13 (S), Unknown: rbcL AJ295871 (Korall and Kenrick, 2002);
(2) Rothfels & al. 3747 (DUKE), Ecuador (Pichincha): rbcL
KT161597, ITS KT161828; Selaginella sertata Spring, Rothfels & al.
3192 (DUKE), Mexico (Jalisco): rbcL KT161598, ITS KT161829;
Selaginella shakotanensis (Franch. ex Takeda) Miyabe & Kud^
o (1)
Iwatsuki 53 (US), Japan (Nagano): rbcL AF419059 (Arrigo et al.,
2013), ITS AF419040 (Arrigo et al., 2013); (2) TNS776371 (TNS),
Japan (Nagano): rbcL AB574652 (Ebihara et al., 2010); Selaginella
sheldonii Maxon, Rothfels & al. 2487 (DUKE), USA (Texas): rbcL
KT161599, ITS KT161830; Selaginella siamensis Hieron., He & Zhou
102 (PYU, CDBI), China (Yunnan): rbcL KT161600, ITS
KT161831; Selaginella sibirica (Milde) Hieron., (1) TNS743691
(TNS), Japan (Hokkaido): rbcL AB574653 (Ebihara et al., 2010); (2)
Kelso 83-222. (COLO), USA (Alaska): rbcL AF419076 (Arrigo et al.,
2013), ITS AF419032 (Arrigo et al., 2013); Selaginella sichuanica
H.S. Kung (1) Chu & al. 7385 (PYU), China (Sichuan): rbcL
KT161602; (2) Luo 1349 (CDBI), China (Guizhou): rbcL KT161601;
Selaginella cf. sichuanica, Zhang & al. DJY04930 (CDBI), China
(Sichuan): rbcL KT161603, ITS KT161832; Selaginella silvestris
Aspl. Rothfels & al. 08-202 (DUKE), Costa Rica (Heredia): rbcL
KT161604, ITS KT161833; Selaginella simplex Baker, Tehler 8038
(S), Unknown: rbcL AJ295888 (Korall and Kenrick, 2002); Selaginella sp_A, Knapp 3260 (P), China (Taiwan): rbcL KT161605,
ITS KT161834; Selaginella sp_B, (1) Zhang & al. 6570 (CDBI, MO,
30
Xin-Mao Zhou et al. / Cladistics 0 (2015) 1–30
VNMN, PYU), Vietnam (Phu Tho): rbcL KT161607, ITS
KT161835; (2) Zhang & al. 6925 (CDBI, MO, VNMN, PYU), Vietnam (Ha Giang): rbcL KT161606, ITS KT161878; Selaginella sp_C
(1) Zhang 5888 (CDBI), China (Guizhou): rbcL KT161608, ITS
KT161879; (2) Zhang 5909 (CDBI), China (Guizhou): rbcL
KT161609, ITS KT161836; (3) Zhang 6055 (CDBI), China (Guizhou): rbcL KT161610, ITS KT161837; Selaginella sp_D, Wood 11034
(PTBG), Society Islands (Huahine): rbcL KT161611, ITS KT161838;
Selaginella sp_E,Wood 13942 (PTBG), F.S.M. (Caroline_Is., Kosrae): rbcL KT161612, ITS KT161839; Selaginella sp_F, Wood 13673
(PTBG), F.S.M. (Caroline_Is., Kosrae): rbcL KT161613, ITS
KT161840; Selaginella stauntoniana Spring, (1) Kenrick s.n. (S),
Unknown: rbcL AJ295869 (Korall and Kenrick, 2002); (2) Quan 1
(PYU), China (Henan): rbcL KT161615, ITS KT161880; (3) Zhao
169 (CDBI), China (Beijing): rbcL KT161614, ITS KT161841; Selaginella steyermarkii Alston, Williams 23005 (US), Guatemala
(Quezaltenango): rbcL AF419088 (Arrigo et al., 2013), ITS
AF419034 (Arrigo et al., 2013); Selaginella suavis Klotzsch, Tehler
7929 (S), Unknown: rbcL AJ295886 (Korall and Kenrick, 2002); Selaginella sulcata (Desv. ex Poir.) Spring ex Mart., Tehler 7939 (S),
Unknown: rbcL AJ295887 (Korall and Kenrick, 2002); Selaginella
superba Alston, Chu & al. 19425 (PYU), China (Yunnan): rbcL
KT161616, ITS KT161842.
Selaginella tama-montana Seriz., (1) TNS769195 (TNS), Japan
(Mie): rbcL AB574654 (Ebihara et al., 2010); (2) Knapp 3257 (P),
China (Taiwan): rbcL KT161617, ITS KT161843; Selaginella tamariscina (P. Beauv.) Spring, (1) TNS759348 (TNS), Japan (Okinawa):
rbcL AB574655 (Ebihara et al., 2010); (2) Shurba 5157 (S),
Unknown: rbcL AJ295861 (Korall and Kenrick, 2002); (3) Unknown
Peninsula Malaysia: rbcL JF950018 (Herrmann et al., 2011);
Selaginella tenuifolia spring, Zhang & al. 6780 (CDBI, MO, VNMN,
PYU), Vietnam (Bac Kan): rbcL KT161618, ITS KT161844;
Selaginella tortipila A. Braun, (1) Hill 20496 (KANU), USA (South
carolina): rbcL AF419081 (Arrigo et al., 2013), ITS AF419007
(Arrigo et al., 2013); (2) Rothfels & al. 2718 (DUKE), USA (North
Carolina): rbcL KT161619, ITS KT161845; Selaginella trachyphylla
A. Braun ex Hieron., Chu & al. 5841 (PYU, CDBI), China (Yunnan): rbcL KT161620; Selaginella trichophylla K.H. Shing, (1) Chu &
al. 31925 (PYU), China (Yunnan): rbcL KT161621, ITS KT161847;
(2) Chu & al. 29310 (PYU), China (Yunnan): rbcL KT161622, ITS
KT161846; (3) Zhang & al. 6784 (CDBI, MO, VNMN, PYU), Vietnam (Cao Bang): rbcL KT161624, ITS KT161849; (4) Jiang 318
(PYU, CDBI), China (Hainan): rbcL KT161623, ITS KT161848.
Selaginella uliginosa (Labill.) Spring, Gray & al. 523 (S), Australia
(Tasmania): rbcL AJ010843 (Korall et al., 1999); Selaginella umbrosa
Lem. ex Hieron., (1) Rothfels & al. 08-155 (DUKE), Costa Rica
(Heredia): rbcL KT161625, ITS KT161850; (2) Korall 1998:4 (S),
cult.: rbcL AJ295879 (Korall and Kenrick, 2002); Selaginella uncinata (Desv. ex Poir.) Spring (1) Unknown Peninsula Malaysia: rbcL
EU197126 (Y. Yi, Y. He, and B. Tan, unpublished); (2)
TNS9508552 (TNS), Japan (Tokyo): rbcL AB574656 (Ebihara et al.,
2010); (3) Zhang & Zhou DJY04101 (CDBI), China (Sichuan): rbcL
KT161626, ITS KT161852; Selaginella cf. uncinata, Rothfels & al.
08-137 (DUKE), introduced to Costa Rica (Puntarenas): rbcL
KT161423, ITS KT161851; Selaginella underwoodii Hieron., Therrien
s.n. (KANU), USA (Colorado): rbcL AF419077 (Arrigo et al.,
2013), ITS AF419031 (Arrigo et al., 2013); Selaginella utahensis
Flowers, Windham 96-052 (UT), USA (Utah): rbcL AF419067 (Arrigo et al., 2013), ITS AF419024 (Arrigo et al., 2013).
Selaginella vardei H. Lev., (1) Zhou 091 (CDBI), China (Sichuan):
rbcL KT161627, ITS KT161856; (2) Chu & al. 29607 (PYU), China
(Yunnan): rbcL KT161628, ITS KT161853; (3) He & al. 81904
(PYU), China (Yunnan): rbcL KT161629, ITS KT161855; (4) Jin
s.n. (PYU), China (Yunnan): rbcL KT161630, ITS KT161854; (5)
Wu s.n. (MO), China (Yunnan): rbcL AF419060 (Arrigo et al.,
2013), ITS AF419041 (Arrigo et al., 2013).
Selaginella wallacei Hieron., (1) Rothfels & al. 2933 (DUKE),
USA (California): rbcL KT161631, ITS KT161858; (2) Rothfels & al.
3852 (DUKE), USA (Oregon): rbcL KT161635, ITS KT161859; (3)
Rothfels & Zylinski 4061 (DUKE), Canada (British Columbia): rbcL
KT161632, ITS KT161860; (4) Therrien s.n. (KANU), USA (Oregon): rbcL AF419065 (Arrigo et al., 2013), ITS AF419035 (Arrigo
et al., 2013); (5) Rothfels & Park 4191 (DUKE), USA (Idaho): rbcL
KT161633, ITS KT161861; (6) Rothfels & al. 4514 (UBC), USA
(Washington): rbcL KT161636, ITS KT161857; (7) Rothfels & Rushworth 4196 (DUKE), USA (Idaho): rbcL KT161634, ITS KT161862;
Selaginella wallichii (Hook. & Grev.) Spring, Zhang & al. 6744
(CDBI, MO, VNMN, PYU), Vietnam (Bac Kan): rbcL KT161637;
Selaginella watsonii Underw., (1) Li 1601 (DUKE), USA (Idnho):
rbcL KT161638, ITS KT161863; (2) Windham 91-137 (UT), USA
(Utah & Arizona): rbcL AF419090 (Arrigo et al., 2013), ITS
AF419037 (Arrigo et al., 2013); Selaginella weatherbiana R.M. Tryon
Therrien s.n. (KANU), USA (Colorado): rbcL AF419075 (Arrigo
et al., 2013), ITS AF419006 (Arrigo et al., 2013); Selaginella wightii
Hieron., Faden 76-537 (US), Sri-Lanka (Matale): rbcL AF419062
(Arrigo et al., 2013), ITS AF419018 (Arrigo et al., 2013); Selaginella
willdenowii (Desv. ex Poir.) Baker (1) Korall 1998:11 (S), cult.: rbcL
AJ295893 (Korall and Kenrick, 2002), (2) Wang 90408 (PYU),
China (Guizhou): rbcL KT161639, ITS KT161881; (3) Chu & al.
18474 (PYU), China (Guangxi): rbcL KT161640, ITS KT161864;
Selaginella wrightii Hieron., (1) Rothfels & al. 2480 (DUKE), USA
(Texas): rbcL KT161641, ITS KT161865; (2) Worthington 21748
(KANU), USA (Texas): rbcL AF419089 (Arrigo et al., 2013), ITS
AF419011 (Arrigo et al., 2013).
Selaginella xichouensis W.M. Chu, Chu & al. 13149 (PYU, CDBI),
China (Yunnan): rbcL KT161644, ITS KT161866; Selaginella
xipholepis Baker, (1) Dong 2377 (PYU), China (Guangdong): rbcL
KT161645; (2) Zhang & al. 6668 (CDBI, MO, VNMN, PYU),
Vietnam (Bac Kan): rbcL KT161646, ITS KT161867.
David Lorence
Carl Rothfels