Contribution to the study of the Selaginellaceae of Madagascar Sasa STEFANOVIC & France RAKOTONDRAINIBE École Pratique des Hautes Études, Laboratoire de Phytomorphologie, Muséum national d'Histoire naturelle, 16 rue Buffon, 75005 Paris, France. [email protected] ABSTRACT KEY WORDS A new species of Selaginella, S. sambiranensis, from Madagascar is described Selaginella, Selaginellaceae, and illustrated. The taxonomie position and closest relationships are briefly Madagascar. discussed. RÉSUMÉ MOTS CLÉS Une espèce nouvelle de Selaginella, S. sambiranensis, de Madagascar est Selaginella, décrite et illustrée. La position taxinomique et les relations avec les proches Selaginellaceae, Madagascar. espèces malgaches sont brièvement discutées. ADANSONIA, sér. 3 • 1997 • 19(1) 165 Stefanovic S. & Rakotondrainibe F. About 700 species hâve been attributed to the S. sambiranensis, belongs to the subgenus monogeneric Family Selaginellaceae. They are Heterostachys Baker. widely distributed throughout the world, but the The descriptive terms referring to shape, surface vast majority occur in tropicaJ and subtropical and structure of spores follow terminology used areas. The last complété account o( rhe family in by Tryon & Lugardon (1991). Madagascar and Comoros made by AtsTON (1932) listed 13 spccies of Selaginella occurrïng in that area. Five additional Malagasy taxa were established, one by TRYON (1955), one by RAUH Selaginella sambiranensis Stefanovic & &C HACEMANN (1991) and three by STEFANOVIC Rakotondrainibe, sp. nov. & Rakotondrainibe (1996). During révision of Species haec. inter species subgeneris Heterostachys this family for the Flore de Madagascar et des Baker, habitu ad S. hildebrandtii A. Braun ex Hieron. Comores, necessiraded by the increase in avail- similis, sed apicibus folioram mediorum acutis (non acu- able collections from rhe last 40 years (specimens tninatis) ab ea dijfert. hâve been studied from P, BM), a distinct species was discovered and is described to make the TYPE.—Perrier de la Bâthie 8291 bis, Madagascar, name available for the Flora treatment. vallée du Marofototra, base du Mt. Bekolosy, massif Following rhe most recent classification of the du Manongarivo, Sambirano, Mar. 1909 (holo-, P; genus Selaginella (JLRMY 1986), the new species, iso-, BM). Fig. 1.—Selaginella sambiranensis Stefanovic & Rakotondrainibe: A, habit; B, enlarged dorsal view showing acute médian leaves and denticulate latéral leaves; C, strobilus. (Perrier de ia Bâthie 8291 bis). Drawn by J.-F. Dejouanet. 166 ADANSONIA, sér. 3 • 1997 • 19(1) Selaginellaceae of Madagascar Fig. 2.—Scanning électron (SEM) micrographs of the spores of Selaginella sambiranensis. A, megaspore; B, microspore. (Perrier de la Bâthie 8291 bis). Plant without rhizome, forming mats. Main proximal and distal face, without any back- steam suberect to erect, 4-10 cm long, outline ground pattern.—Fig, 1,2A,B). lanceolate, branched, provided with rhizopbores, Branches hifurcated 1-2 timcs. Rhizophores dor¬ Paratyi’es.—Madagascar: Decary 2137, sal, situated in the lower hall of the stem, 1-3 cm Maromandia, 9 June 1923 (P); Guillaume! 2170, long and 0.2-0.4 mm in diam., straw ycllow ro Manongarivo, à 13 km environ de la Maevarano ou pale green, dichotomizing 2-3 rimes. Lcaves 70 km d'Antsohihy sur la route d’Ambanja, 2 Aug. dimorphic, pale green, herbaccoas, widely spaced 1968 (P); Perrier de la Bdthie 8275, bords du on the main stem, spaced to comiguous tovvard Manongarivo, Sambirano, June 1909 (P, BM); Rakotonarainibe 1131, massif du Manongarivo, au S the extremity of the axes, midrib apparent, d'Ambalafary, sur un plateau, 150-200 m, 1 Apr. Latéral lcaves subequal, oblong, 1.2-2,3 x 1991 (P); Rakotorrdratnibe 1132, l.c., 29 Mar. 1991 0.6-1.2 mm, the base uncqlial and blunt, the (P). apex subblunt to acutc, the margin subentire to dcnticulate ail around the leaf. Axilar leaves simi- Distribution and habitat.—Ail collections lar to latéral but equal. Médian leaves subequal, are from Domaine Sambirano of northwest ovate-oblong, 0.9-1.3 x 0.4-0,7 mm, the base Madagascar, Massif de Manongarivo, where this oblique, the apex acute, non acuminate, the mar- specîes grows in colonies on rocks in shade, at an gins denticulate, Strobüî solitary, inserted termi¬ élévation of 150-200 m. nais on main stem and branch tips, bilateral, resupînate, 2-4.5 X 1.5-2.5 mm. Sporophylls Bilateral and resupinated strobili and dimor¬ dimorphic. Dorsal sporophylls obiong-lanceola- phic sporophylls place this species, subgenus te, 1-1.5 X 0.4-0.6 mm, keelcd, the keel well Hererosiachys Baker, according ro the taxonomie developed and dentatc, the base blunt. the apex arrangement of the genus Selaginella proposed by subblunt to acute, the margins denticulate. JERMY (1986). Ventral sporophylls ovate, 0.9-1.1 X 0,4- 0.6 mm, slightly or not keeled, the base blunt, S. sambiranensis resembles the Comorian spe¬ apex progrcssiveJy acuminate, margins dentate- cies S. hildebrandtii A. Braun ex Hieron., winch ciliate. Megaspores pale yellow, 180-240 pm in belongs to the sanie subgenus, in the lanceolate diameter, terrahedral-globose, trilete, with laesura outline of its habit and shape and position of 3/4 to nearly equal the radius, the surface broken lareral leaves. The two species çan be distingui- reticulate on both proximal and distal face, shed easily, because the médian leaves of the for¬ Microspores red, 31-32 pm in diameter, tetrahe- mer are acute and denticulate, whereas the latter dral-globose, trilete, with laesura equaling the has acuminate and dentate médian leaves. radius, the surface complctly laevigate on both S. sambiranensis is characterized by latéral leaves ADANSONIA, sér. 3 • 1997 • 19(1) 167 Stefanovic S. & Rakotondrainibe F. with both margins subemire to denticulate, REFERENCES while, S. bildebrandtii has the acroscopic margin ALSTON A.H.G. 1932.—Selaginellaceae, in of latéral leaves dentate and the basiscopic mar¬ C. CHRISTENSEN (ed.), The Pteridophyta of gin entire. Madagascar. Dansk Bot. Ark. 7: 193-200. The species is named after Domaine Jermy A.C. 1986.—Subgeneric names in Selaginella. Sambirano, the type locality. Fem Gaz. 13: 117-118. RAUH W. & Hagemann W. 1991.—Selaginella moratii, spec. nova (Selaginellales), a remarkable new species front Central Madagascar. PL Syst. Evol. 176: 205-219. Acknowledgments Stefanovic S. & Rakotondrainibe F. 1996.—New We are grateful to A. Le Thomas (Laboratoire de taxa and a new rank of Selaginella (Selaginellaceae) Phytomorphologie, Ecole Pratique des Hautes Études) from Madagascar and the Comoros. Novon 6: 203- for support and facilities, critical continents on the 209. manuscript and improvement of the Latin diagnosis. Tryon A.F. & Lugardon B. 1991.—Spores of the The curator of BM graciously loaned specimens and Pteridophyta. Selaginellaceae: 606-621, Springer- types, as well the curator of P. The senior author was Verlag, New York, etc. supported by Open Society Institute Supplementary Tryon R.M. 1955.—Selaginella rupestris and its allies. Grant Program FR-134-95/96YU. Ann. Missouri Bot. Gard. 42: 1-99. Manuscript received 29 August 1996; revised version accepted November 1996. 168 ADANSONIA, sér. 3 • 1997 • 19(1)