A new Uvaria L. species (Annonaceae) from northern Mozambique Thierry DEROIN Muséum national d’Histoire naturelle, Département Systématique et Évolution (UMR 7205) case postale 39, 57 rue Cuvier, F-75231 Paris cedex 05 (France) deroin@mnhn.fr Mervyn LÖTTER Restoration and Conservation Biology Research Group, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, PO WITS 2050 (South Africa) mervyn.lotter@gmail.com Deroin T. & Lötter M. 2013. — A new Uvaria L. species (Annonaceae) from northern Mozambique. Adansonia, sér. 3, 35 (2): 227-234. http://dx.doi.org/10.5252/a2013n2a4 KEY WORDS Cabo Delgado, new species, systematics, Rovuma River, Critically Endangered. ABSTRACT A new species Uvaria rovumae Deroin & Lötter, sp. nov. is described, illustrated and mapped from Cabo Delgado Province in northern Mozambique. Its morphology, as well as systematic affinities, habitat and conservation status are briefly discussed. Very similar to U. tanzaniae Verdc. by its habit, it differs mainly by its free sepals, inner petals slightly unguiculate and a high carpel number (>35). Uvaria rovumae Deroin & Lötter, sp. nov. is known only from a handful of individual plants in one location near Nangade, making it “Critically Endangered” (CR) following IUCN Red List categories and criteria. MOTS CLÉS Cabo Delgado, espèce nouvelle, systématique, rivière Rovuma, danger critique d’extinction. RÉSUMÉ Une nouvelle espèce d’Uvaria L. (Annonaceae) du nord du Mozambique. Uvaria rovumae Deroin & Lötter, sp. nov. est décrite comme nouvelle espèce de la province de Cabo Delgado (Nord du Mozambique), illustrée et cartographiée. Sa morphologie, ainsi que ses affinités systématiques, son habitat et son statut de conservation sont brièvement discutés. Proche, par son port, de Uvaria tanzaniae Verdc., U. rovumae Deroin & Lötter, sp. nov. en diffère principalement par ses sépales libres, ses pétales internes un peu onguiculés et ses carpelles plus nombreux (>35). Ce taxon n’est représenté que par un petit nombre d’individus sur une seule dition près de Nangade, et peut être considéré « en danger critique d’extinction » (CR) selon les catégories et critères de la Liste rouge de l’UICN. ADANSONIA, sér. 3 • 2013 • 35 (2) © Publications Scientifiques du Muséum national d’Histoire naturelle, Paris. www.adansonia.com 227 Deroin T. & Lötter M. INTRODUCTION With c. sixteen recognized species, Uvaria L. is the largest genus in the family for the tropical East African flora, but its taxonomy remains imperfectly known (Robson 1960; Verdcourt 1971; Johnson et al. 1999). Taxonomic difficulties in the group may, at least in part, be due to a complex biogeographical history during the Oligocene or Early Miocene, involving both Africa and Madagascar, changes in sea currents and fruit dispersal by primates, as recently demonstrated by Zhou et al. (2012). Uvaria rovumae Deroin & Lötter, sp. nov., was first collected by one of us (Mervyn Lötter) in March 2009 during a plant survey in Cabo Delgado province (northern Mozambique). A collection of a fruiting specimen was made, which ML provisionally referred to as Uvaria tanzaniae Verdc., but suspected to be a new species. ML returned to the site again in January 2012 and collected flowering material, which was sent to the senior author who confirmed that it was indeed an undescribed species. MATERIAL AND METHODS Two collections – one flowering, the other fruiting – were made from the same locality, two years apart. As usual for the family, flowers were rather sparse on the twigs, and thus a single flower – a little time before the anthesis (Fig. 1E) – was available on the isotype deposited at P. This was then rehydrated and restored in NH4OH 10%aq. at 60°C, fixed in FAA and dissected in the usual preservative (Alcohol-Water-Glycerol, at equal volumes). Each stage of the dissection was drawn, and all floral members were mounted on slides and filed with the isotype sheet kept at P herbarium. Examination of a dried mature fruit was found to be enough for the description. Several photographs taken on the field were available, allowing a correct interpretation of floral and fruit morphology. 228 SYSTEMATICS Uvaria rovumae Deroin & Lötter, sp. nov. (Figs 1; 3; 5) Species habitu cum Uvaria tanzaniae Verdc. valde congruens, sed foliis non hirsutis subtus, pedicellis non obsoletis, calyce non cupuliformi sesquilatiori cum sepalis omnino liberis, petalis ellipticis vs. ovatis, neque tomentosis, plusminusve sesquilongioribus, intimis leviter unguiculatis, carpellis numerosissimis cum ovulis c. 10 vs 20 biserialibus, mericarpis nullo modo fusiformibus 2 vs.10-seminatis praecipue differt. TYPUS. — Mozambique. Cabo Delgado, Nangade, tall closed woodland, 11°12’05’’S, 39°38’48’’E, 332 m, 6.I.2012, fl., Lötter 2142 (holo-, BNRH ; iso-, K, P[P00700917]!). PARATYPUS. — Mozambique. Cabo Delgado, 16 km south of Nangade, tall mixed closed woodland forest, 11°12.081’ S, 39°38.796’ E, 332 m, sandy soil, 23.III.2009, fl., Lötter & Turpin 1763 (K, LMA, P[P00700918]!). ETYMOLOGY. — The specific epithet refers to the nearby Rovuma River. DESCRIPTION Scrambling liana c. 3-4 m tall, young branchlets rusty stellate-pubescent, later glabrous, pale brown, sparsely lenticellate. Leaves held in one plane; leafblades elliptic or obovate, 55-126 × 27-61 mm, obtuse acuminate or emarginate at the apex, rounded or somewhat cordate at the base, papery, densely pubescent when young, then glabrous above and beneath except for a few stellate hairs on the midrib and secondary veins (8-11 pairs), all veins slightly printed above, prominent beneath; petiole 3-6 mm long, stellate-pubescent. Inflorescence leaf-opposed, peduncle c. 7 mm long, flowers 1(-2); bracteoles 2, c. 10 × 6.5 mm, pubescent outside, lower bracteole rounded slightly unguiculate, upper one elliptic. Torus as a depressed cylinder c. 14 mm in diameter, flat convex above. Perianth members basically with 5 primary nerves and a dense brochidodromous venation. Sepals broadly ovate, c. 11 × 15 mm, obtuse, free, pubescent outside, pale green. Petals subequal, gold yellow with a greenish tinge, apex obtuse or rounded, spreading, reflexed at the end of anthesis, the outer elliptic c. 18 × 11.5 mm, sparsely pubescent outside, the inner narrowly elliptic with ADANSONIA, sér. 3 • 2013 • 35 (2) A new Uvaria L. species (Annonaceae) from Mozambique P K L M Q R N D A O B E C J I F G H Fig. 1. — Uvaria rovumae Deroin & Lötter, sp. nov.: A, flowering twig; B, C, leaves (abaxial side); D, detail of the middle of leaf-blade, with domatia; E, flower just before the anthesis; F,G, lower and upper bracteoles; H, sepal; I, J, outer and inner petal; K-M, stamen, in abaxial, side and adaxial views; N, outer stamen, adaxial view; O, receptacle and gynoecium; P, Q, carpel in abaxial and adaxial views; R, carpel in longitudinal section. Lötter 2142 (iso-, P). Drawing Thierry Deroin. Scale bar: A-C, E, 1 cm; D, 1 mm; F-J, O, 5 mm; K-N, P-R, 2 mm. ADANSONIA, sér. 3 • 2013 • 35 (2) 229 Deroin T. & Lötter M. Fig. 2. — Uvaria rovumae Deroin & Lötter, sp. nov.: two inner petals congenitally fused. Lötter 2142 (iso-, P). Drawing Thierry Deroin. Scale bar: 5 mm. a broad claw c. 20 × 11 mm, glabrous outside. Stamens numerous (c. 300, arranged in 6-7 whorls), linear c. 2 × 0.6 mm, latrorse, connective head truncate and minutely papillose, enlarged above narrow pollen sacs. The outermost stamens more rounded, c. 1.5 mm long. Carpels slender, c. 50, ovary c. 2 mm long, with scattered stellate hairs on the abaxial side, ovules c. 10, biseriate; stigmas horseshoe convoluted c. 0.5 mm thick, covered with simple hairs. Fruit a pseudosyncarp ellipsoid in outline, c. 45 mm in diameter and 30 mm tall, pale yellow, borne on a peduncle c. 12 mm long and 3 mm thick, sepals persistent reflexed but not accrescent, mericarps c. 50 obovoid and apically rostrate, covered by sparse stellate hairs, 13-18 mm long, crowded on a globular receptacle by very short stipes (2 mm or less). Seeds 2 per mericarp, ellipsoid-irregular c. 6-8 × 4 × 4 mm, with a glossy reddish brown testa showing a weak pattern of endosperm rumination. DISTRIBUTION, ECOLOGY AND PHENOLOGY Uvaria rovumae Deroin & Lötter, sp. nov., appears to be a range-restricted species, hitherto only recorded from the dense understory of a single large Newtonia paucijuga (Harms) Brenan tree, about 25 km south of the Rovuma River 230 near Nangade, 63 km north of Mueda (Fig. 4). The surrounding vegetation was once probably tall semi-deciduous closed woodland or dry deciduous forest, but this has now largely been transformed to a mosaic of open to closed semideciduous woodland with isolated small patches of semi-deciduous forest. Forty-five years ago, Wild & Barbosa (1967) classified the vegetation in this area as Dry deciduous Lowland Forest. Our new species now only occurs in one of the very small remnant forest/thicket patches. Some of the associated woody species occurring with Uvaria rovumae Deroin & Lötter, sp. nov., include: Newtonia paucijuga, Bombax rhodognaphalon K.Schum. ex Engl., Millettia stuhlmannii Taub., Strychnos myrtoides Gilg & Busse, Vismianthus punctatus Mildbr., Whitfieldia orientalis Vollesen, Rinorea welwitschii (Oliv.)Kuntze subsp. tanzanica Grey-Wilson, and Streblus usambarensis (Engl.) C.C.Berg. Floral biology (Fig. 3B-D) conforms to the pattern typical of Uvaria: no pollination chamber (Saunders 2009: 578) and strict protogyny, with at first a receptive stigmatic plate covered by a mucilaginous cap (Fig. 3B) then a release of pollen grains (Fig. 3D). CONSERVATION STATUS After several botanical surveys in the region, this new species appears to be restricted to only one very small patch of forest undergrowth in an area to the north Nangade and just south of Mecabua village. This same locality harbours several other species of considerable biogeographic interest, such as two new records for Mozambique; Whitfieldia orientalis (Lötter & Turpin 1764); and Rinorea welwitschii subsp. tanzanica (Violaceae) (Burrows & Burrows 11314). It is also the second only locality of Streblus usambarensis (Moraceae) (Burrows & Burrows 11313) for Mozambique. An undescribed species of Lagynias E.Mey. (Rubiaceae) (Burrows & Burrows 11316) was also found in the same forest patch. The habitat of the first record of the Streblus usambarensis for Mozambique is classified by Wild & Barbosa (1967) as Dry Deciduous Lowland Forest, supporting our opinion that this area was once much more heavily forested. ADANSONIA, sér. 3 • 2013 • 35 (2) A new Uvaria L. species (Annonaceae) from Mozambique A B C D Fig. 3. — Uvaria rovumae Deroin & Lötter, sp. nov., flower morphology: A, floral bud, note the leaf-opposed position; B, C, flower at the ♀ stage, by side and above, petals are spread out; D, flower at the ♂ stage, petals are strongly reflexed, pollen (white) is released by browning dislocating stamens (field photographs Mervyn Lötter). The current site is dependent on the shade from a single large Newtonia paucijuga tree. The logging of this tree would allow light and fire to penetrate this biogeographically important forest patch. A large road running southwards from Nangade to Mueda cuts through part of this once larger forest patch. We suspect that more plants of Uvaria rovumae Deroin & Lötter, sp. nov., may eventually be found in the Rovuma River valley, or even in southern Tanzania. However it is currently only known from less than 5 individuals ADANSONIA, sér. 3 • 2013 • 35 (2) in an area no more than 30 × 30 m. Based on the IUCN Red List categories and criteria version 3.1 (IUCN 2001), a provisional conservation status of Critically Endangered CR B1ab(iii); C1; D1 is thus proposed. MORPHOLOGICAL REMARKS The dissected flower of Uvaria rovumae Deroin & Lötter, sp. nov., showed two puzzling features: 1) Two of the three inner petals were accidentally connate, as demonstrated by the merging of the 231 Deroin T. & Lötter M. 38°E 39° 40° 41° 42° 8°S Indian Ocean 9° TANZANIA 10° 11° 12° 13° MOZAMBIQUE 14° 15° Fig. 4. — Map showing the known distribution of Uvaria rovumae Deroin & Lötter, sp. nov. most lateral veins (Fig. 2). A basal fusion of petals was previously reported in some species of the genus (van Heusden 1992: 150), but did not involve the primary vasculature. 2) Some of the most outer stamens are shorter and rounded (Fig. 1N), rather reminiscent of staminodes, frequent in Annonaceae (Saunders 2009: 584) and usually present in several – especially Asiatic –Uvaria species (van Heusden 1992: 150), although they are here fertile. Uvaria rovumae Deroin & Lötter, sp. nov. resembles members of the Uvaria angolensis group, as expanded by Johnson et al. (1999), in that its petals become strongly revolute during anthesis, but differs markedly by its free sepals and more numerous carpels (>35). 232 If the cupuliform calyx is not considered, U. rovumae appears intermediate between the two subgroups (U. tanzaniae Verdc. + U. angolensis Oliver) and (U. lucida Bentham + U. puguensis D.M. Johnson), being similar to the first in habit and petal size, much more to the second by the scattered pubescence of flowers. The similarity is striking with U. puguensis, especially in the torus morphology (Johnson et al. 1999; Fig. 2E) and petal colour (“yellow-green to pale orange-yellow”), as well as trichome, but the flower is much smaller (torus c. 5 vs 14 mm diam.), exhibiting a low stamen number (30-40 vs 300) with stretched quadrate vs truncate head connectives. In their phylogenetic reconstruction of Uvaria, Zhou et al. (2012: 325) show that all African and Malagasy species are in a same clade II, splitting off during the Miocene, at c. 17.0 Ma. It is noteworthy that sepals are usually free or slightly connate at the base in Malagasy species (Cavaco & Keraudren 1958: 7; Deroin & Gautier 2006), as in U. rovumae. A cupuliform calyx is a good character in an identification key, but cannot be used for outlining natural units. Perhaps is it possible to explain the free sepals of U. rovumae by a shift in the gene expression during floral morphogenesis (Saunders 2009: 586). The synsepaly character, expected in this species-group, tends to be then expressed more inside in the perianth, while outer stamens are coming close to staminodes. It is possible that the increase of stamen and carpel numbers is correlated. The pseudosyncarpic fruit (Fig. 5) is similar to that of Uvaria scabrida Oliv., a West African species (Le Thomas 1969: 77). It is noticeable that in both species almost no carpel abortion occurs during fruit set. However in U. scabrida the floral receptacle is already globular, while in U. rovumae Deroin & Lötter, sp. nov. it appears flattened. On the other hand, if compared with the related U. tanzaniae Verdc., only 20% of the ovules evolve in mature seeds and so the mericarps are not fusiform and even very slightly lomentaceous (Verdcourt 1986: 287). These structural differences entail likely divergences in dispersal biology between these close species. ADANSONIA, sér. 3 • 2013 • 35 (2) A new Uvaria L. species (Annonaceae) from Mozambique A B Fig. 5. – Uvaria rovumae Deroin & Lötter, sp. nov.: details of fruit. A, fruiting twig; B, cross section of the pseudosyncarp, Lötter & Turpin 1763 (field photographs Mervyn Lötter). ADANSONIA, sér. 3 • 2013 • 35 (2) 233 Deroin T. & Lötter M. Acknowledgements We would like to thank John Burrows for comments on the earlier manuscript and Quentin Luke for views on the taxonomy of Uvaria rovumae Deroin & Lötter, sp. nov.. We would also like to acknowledge Pro-Natura International and the Muséum national d’Histoire naturelle in Paris, who kindly contributed financial support towards the March 2009 botanical expedition in Cabo Delgado Province. The National Herbarium (LMA), Instituto de Investigação Agrária de Moçambique, are gratefully acknowledged for supporting our botanical exploration in Mozambique and for the necessary collecting permits. The Mpumalanga Tourism & Parks Agency are thanked for allowing the second author time off to participate in the botanical survey in Mozambique. We also wish to thank Jonathan Timberlake, and an anonymous reviewer for constructive comments and suggestions. REFERENCES CAVACO A. & KERAUDREN M. 1958. — Annonacées. In Humbert H. (ed.) Flore de Madagascar et des Comores 78, Muséum national d’Histoire naturelle, Paris. DEROIN T. & GAUTIER L. 2006. — Deux Uvaria (Annonaceae) nouveaux du Sambirano, Madagascar. Candollea 61: 51-60. HEUSDEN E. C. H. VAN 1992. — Flowers of Annonaceae: morphology, classification, and evolution. Blumea (Supplement) 7: 1-218. IUCN 2001. — IUCN Red List Categories and Criteria: version 3.1. IUCN Species Survival Commission. IUCN, Gland and Cambridge, 30 p. JOHNSON D. 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