Two New Species of Cyperus (Cyperaceae) from the Zambezian Region
of Africa
Kenneth Bauters, Marc Reynders, Isabel Larridon,*
Wim Huygh, and Paul Goetghebeur
Ghent University, Department of Biology, Research Group Spermatophytes,
K. L. Ledeganckstraat 35, 9000 Gent, Belgium. *Author for correspondence:
isabel.larridon@ugent.be
Two New Species of Cyperus (Cyperaceae) from the Zambezian Region
of Africa
Kenneth Bauters, Marc Reynders, Isabel Larridon,*
Wim Huygh, and Paul Goetghebeur
Ghent University, Department of Biology, Research Group Spermatophytes,
K. L. Ledeganckstraat 35, 9000 Gent, Belgium. *Author for correspondence:
isabel.larridon@ugent.be
ABSTRACT . Cyperus absconditicoronatus Bauters,
Reynders & Goetgh. and C. unispicatus Bauters,
Reynders & Goetgh., two new species of Cyperus L.
(Cyperaceae) from Angola and Zambia, are recognized. Cyperus absconditicoronatus is a tall species
(55–100 cm) characterized by a scaled rhizome, a
single terminal capitulum, a ciliated spikelet bract,
and deciduous spikelets. Cyperus unispicatus can be
recognized by a swollen and fibrous stem base growing
from slender rhizomes, a single terminal spike, and
short involucral bracts. The taxa are described and
illustrated, and differences with the closest resembling species are discussed.
Key words: Africa, Angola, Cyperaceae, Cyperus,
IUCN Red List, Zambia.
7042/2) of this taxon was found, incorrectly identified
as C. rhynchosporoides Kük.
Mincier (1984: 182) also mentioned the only
known specimen (H. & E. Hess 52/34) of the second
new species, Cyperus unispicatus Bauters, Reynders
& Goetgh., as ‘‘Mariscus sp. nov.’’ He placed this
new species in Cyperus sect. Bulbocaules (C. B.
Clarke) Kük., which is characterized by a swollen
stem base.
The genus Cyperus L. s. str. (Cyperaceae) includes
696 accepted species worldwide (Govaerts et al.,
2008). Cyperus can be recognized by a usually
anthelate inflorescence often with conspicuous involucral bracts, spikelets with several to many fertile
and usually distichous glumes, the rachilla of the
spikelet either persistent or not, the flowers without a
perianth, and a trifid, less often bifid, or rarely
nondivided style.
During the examination of some specimens of
Cyperus in the Ghent University Herbarium (GENT)
as part of ongoing research on the genus by the
authors, several specimens were encountered that
could not be assigned to any known species in the
genus (after identification with Kükenthal, 1935–
1936; Chermezon, 1937; Hooper & Napper, 1972;
Haines & Lye, 1983). One of the specimens (H. & E.
Hess 52/545) was incorrectly identified by Mincier
(1984) as Mariscus albopilosus C. B. Clarke (accepted
name 5 Cyperus albopilosus (C. B. Clarke) Kük.). In
his master’s thesis on the Cyperaceae from Angola, he
mentioned another specimen (H. & E. Hess 52/262) as
‘‘Mariscus sp. nov.’’ (Mincier, 1984: 180). Both
specimens clearly belong to the same new species.
In the herbarium of the National Botanic Garden of
Belgium (BR), a third specimen (M. G. Bingham
Haec species Cypero rhynchosporoidi Kük. et C. albopiloso
(C. B. Clarke) Kük. similis, sed a hoc bracteis involucralibus
3, inflorescentia majore atque nucula oblonga, ab illo
habitu robustiore atque culmo ad basim non incrassato
distinguitur.
doi: 10.3417/2008078
1. Cyperus absconditicoronatus Bauters, Reynders & Goetgh., sp. nov. TYPE: Angola. Bié:
Falls of Cutato River, S of [Kuvango]–Cuchi Rd.,
15 Sep. 1952, H. & E. Hess 52/262 (holotype,
GENT). Figures 1, 2A, B.
Perennial herb; rhizomes 6–9 mm thick, with
conspicuous red-brown scales that split crown-like
as the rhizome thickens; culms 55–100 3 ca. 0.2 cm,
slender, triangular, erect, ciliated with hairs on the
ribs, scabrous, stem base not swollen. Leaves 5 to 8,
all basal, lowest leaves reduced to their sheath;
sheaths to 13 cm, cinnamon colored; highest leaves
with blades; blades rough, 35–65 3 0.5–0.7 cm.
Inflorescence a single, terminal, spherical head, 1.5–
1.6 cm diam.; involucral bracts 3, ciliated on the
edges, 2.5–9.5 3 0.3–0.4 cm. Spikelets deciduous, 5–
8 3 1–1.2 mm; spikelet bract 2–3 3 ca. 1 mm
(measured on folded bract), ciliated on the midrib;
spikelet prophyll 2–3 3 ca. 1 mm (measured on
folded prophyll); glumes 2 per spikelet, distichous;
first glume completely enveloping nutlet, 5–8 mm
long, 12-veined; second glume strongly reduced, 3.5–
4 3 ca. 0.8 mm, midrib white. Flowers 1 per spikelet,
bisexual; stamens 3, anthers ca. 7 mm; style 1–2 mm;
stigma branches 3. Nutlet 5–6 3 ca. 1 mm, oblong,
trigonous, apiculate, black.
NOVON 20: 133–138. PUBLISHED
ON
9 JUNE 2010.
134
Novon
Figure 1. Cyperus absconditicoronatus Bauters, Reynders & Goetgh. —A. Habit. —B. Inflorescence. —C. Spikelet. —D.
Nutlet. —E. Rhizome. —F. Detail of rhizome scales. From the holotype H. & E. Hess 52/262 (GENT).
IUCN Red List category. Cyperus absconditicoronatus should be classified as Data Deficient
(DD) according to IUCN Red List criteria (IUCN,
2001).
Etymology. The epithet of Cyperus absconditicoronatus means ‘‘with hidden crown’’ and
refers to the scales of the rhizome, which split
crown-like.
Volume 20, Number 2
2010
Bauters et al.
Cyperus (Cyperaceae) from Africa
135
Table 1. Morphological comparison of Cyperus absconditicoronatus, C. rhynchosporoides, C. unispicatus, and
C. stramineoferrugineus.
C. absconditicoronatus
C. rhynchosporoides
C. unispicatus
C. stramineoferrugineus
Basal parts
Culm base
Culms, dimensions
(cm)
Culms, section
rhizomes, 6–9 mm thick rhizomes, 3 mm thick
not swollen
slightly swollen
10–50 3 0.1–0.2
55–100 3 ca. 0.2
slender rhizome
caespitose
swollen: 0.5–0.9 cm
swollen: 0.9–1.3 cm
(9–)20–32 3 0.05–0.1 10–15 3 0.05–0.1
triangular
triangular to rounded
triangular
Leaf blade,
dimensions (cm)
Inflorescence
Capitulum,
diam. (cm)
Involucral bracts
Involucral bracts,
length (cm)
Spikelets
Spikelets,
dimensions (mm)
Glumes, length (mm)
Spikelet bracts
Nutlet, dimensions
(mm)
Distribution
35–65 3 0.5–0.7
ca. 30 3 0.3–0.5
(2–)5–14 3 0.1–0.2
triangular, slightly
compressed
5–15 3 0.03–0.1
spherical capitulum
1.5–1.6
spherical capitulum
ca. 1
ovate capitulum
0.4–0.7
spherical capitulum
0.6–1
3
2.5–9.5
2 to 4
3–6
1 to 2
0.7–1.6
2 to 3
3–5
2 glumes, 1 flower
5–8 3 1–1.2
2 glumes, 2 flowers
5–6 3 ca. 1
3 flowers
2–3.6 3 ca. 1
4 to 5 flowers
3–5 3 ca. 2
5–8
ciliated on midrib
5–6 3 ca. 1
4.5–5
not ciliated on midrib
NA
1.5–2.5
not ciliated on midrib
1.1–1.3 3 0.5–0.8
3.5–4
NA
1.5–1.8 3 1–1.2
Angola, Zambia
Angola, Zambia, Congo
Angola
Tanzania
NA, data not available.
Figure 2. A, B. SEM micrographs of Cyperus absconditicoronatus Bauters, Reynders & Goetgh. —A. Spikelet. —B. Nutlet.
C, D. SEM micrographs of C. unispicatus Bauters, Reynders & Goetgh. —C. Nutlet. —D. Nutlet epidermal cells.
136
Novon
Figure 3. Cyperus unispicatus Bauters, Reynders & Goetgh. —A. Habit. —B. Inflorescence. —C. Spikelet. —D. Nutlet.
—E. Plant bases. From the holotype H. & E. Hess 52/34 (GENT).
Relationships. Cyperus absconditicoronatus is a
tall species characterized by a distinctly scaled
rhizome, deciduous spikelets, and a ciliated spikelet
bract. The closest resemblance was found in the
species C. rhynchosporoides, the type of Cyperus sect.
Ochrocephali Kük. (Kükenthal, 1935–1936). However, C. rhynchosporoides is much smaller in all aspects
and has a slightly swollen stem base (Table 1). As
Volume 20, Number 2
2010
Bauters et al.
Cyperus (Cyperaceae) from Africa
mentioned, Mincier (1984) identified one of the
specimens of C. absconditicoronatus as C. albopilosus.
However, C. albopilosus has a much smaller capitate
inflorescence, an ovate nutlet, and only two involucral
bracts.
Based on its morphology, C. unispicatus could be
classified in Cyperus sect. Bulbocaules subsect.
Kyllingiformes Kük. This group consists of perennial
herbs with triangular, glabrous (seldom hairy) culms.
The stem base is swollen and covered with the
sometimes fibrous remains of old leaf sheaths. Most
species have thick rhizomes, although some have
stolons (C. chevalieri Kük.). The inflorescence always
consists of a dense spherical or irregular capitulum.
The deciduous spikelets are elliptical to lanceolate
with one to six flowers.
Discussion. Cyperus absconditicoronatus and C.
unispicatus are both found in miombo woodlands in
the Zambezian region of Africa. Although only known
from a few localities, the new species are potentially
present throughout this still poorly known ecoregion,
which ranges from Angola to the shores of Lake
Victoria in Tanzania.
Both species are characterized by deciduous
spikelets and a head-like contracted inflorescence.
In addition, Cyperus absconditicoronatus has spikelets
on which only one nutlet matures. This combination of
characters can be found in various lineages within
Cyperus (especially in the chlorocyperoid clade) such
as Cyperus sect. Bulbocaules, Cyperus sect. Ochrocephali, Kyllinga Rottb., Lipocarpha R. Br., and
Ascolepis Nees ex Steud. Homologies of the inflorescences of these taxa are still unclear due to the
unresolved phylogeny of the Cyperus clade with
chlorocyperoid anatomy to which these species
belong. It is thus premature to place the two new
species in any of the known subdivisions, and further
study with additional molecular markers is needed to
reveal the exact position of the new species.
Nevertheless, the two new species can be easily
distinguished from all other Cyperus species based on
morphological evidence.
Paratypes. ANGOLA. Bié: Baixo [Kuvango], 30 km N of
Caiundo, N of Mission Capico, 1200 m, 31 Jan. 1952, H. &
E. Hess 52/545 (GENT). ZAMBIA. North-Western Province: Mwinilunga Distr., Wanyizenzi, 7 Jan. 1991, M. G.
Bingham 7042/2 (BR).
2. Cyperus unispicatus Bauters, Reynders &
Goetgh., sp. nov. TYPE: Angola. Huı́la: near
Mupa Catholic Mission in Cuanhama, 228 km
S of [Kuvango], 1250 m, 9 Sep. 1952, H. &
E. Hess 52/34 (holotype, GENT). Figures 2C,
D, 3.
Haec species Cypero stramineoferrugineo Kük. similis, sed
ab eo culmo altiore, inflorescentia densiore atque spiculis 3floris distinguitur.
Perennial herb, forming slender rhizomes; rhizomes dark brown, 15–30 3 1–1.5 mm; stem base
swollen, 5–9 mm wide, covered in fibrous remains
of old leaf sheaths; culms (9–)20–32 3 0.05–0.1 cm,
slender, triangular, glabrous. Leaves 5 to 9, all
basal, sheaths up to 4 cm long, blades (2–)5–14 3
0.1–0.2 cm, ciliated on the edges and midrib. Inflorescence a single terminal capitate spike, slightly
pseudolateral by its involucral bract; spike ovate,
4–7 3 (0.5–)0.9–1 mm; involucral bracts 1 or 2,
largest 0.7–1.6 3 0.07–0.1 cm, second involucral
bract strongly reduced. Spikelets deciduous but
bract and prophyll persistent, 2–3.6 3 ca. 1 mm;
glumes 1.5–2.5 3 ca. 1 mm, distichous. Flowers 3
per spikelet; stamens 3; style branches 3. Nutlet
obovate, 1.1–1.3 3 0.5–0.8 mm, triangular, apiculate.
IUCN Red List category. Cyperus unispicatus
should be classified as Data Deficient (DD) according
to IUCN Red List criteria (IUCN, 2001).
Etymology. The epithet of Cyperus unispicatus
means ‘‘with one spike’’ and refers to the single
terminal spike.
Relationships. Cyperus unispicatus is characterized by a swollen stem base on a slender rhizome and
a single terminal spike with short involucral bracts.
Cyperus unispicatus most closely resembles C. stramineoferrugineus Kük. (Kükenthal, 1935–1936;
Haines & Lye, 1983). However, the latter species
has a less dense, capitate inflorescence, a shorter
culm, and spikelets with four to five flowers (Table 1).
137
Acknowledgments. We particularly thank Jan
Rammeloo, the director of the National Botanic
Garden of Belgium, for the use of the SEM, as well
as Frank Van Caeckenberghe for his expertise in
taking the SEM micrographs. We thank the curator of
BR for the loan of material.
Literature Cited
Chermezon, H. 1937. Cypéracées in H. Humbert (editor),
Flore de Madagascar, 29e fam. Imprimerie Officielle,
Tananarive.
Govaerts, R., D. A. Simpson, P. Goetghebeur, K. L. Wilson,
T. Egorova & J. Bruhl. 2008. World Checklist of
Cyperaceae. The Board of Trustees of the Royal Botanic
Gardens, Kew. Published on the Internet; ,http://www.
kew.org/wcsp/monocots/., accessed 16 June 2008.
Haines, R. W. & K. A. Lye. 1983. The Sedges and Rushes of
East Africa. East African Natural History Society, Nairobi.
138
Novon
Hooper, S. S. & D. M. Napper. 1972. Cyperaceae. Pp.
278–349 in F. N. Hepper (editor), Flora of West Tropical
Africa, Vol. 3. Crown Agents for Overseas Governments
and Administration, London.
IUCN. 2001. IUCN Red List Categories and Criteria, Version
3.1. Prepared by the IUCN Species Survival Commission.
IUCN, Gland, Switzerland, and Cambridge, United Kingdom.
Kükenthal, G. 1935–1936. Cyperaceae–Scirpoideae–
Cypereae in A. Engler (editor), Das Pflanzenreich, Regni Vegetabili Conspectus 4(20). H. R. Engelmann,
Stuttgart.
Mincier, A. 1984. Bijdrage tot de kennis van de Cyperaceae
van Angola. Master’s Thesis, Ghent University, Ghent,
Belgium.