New combinations and new names in Malagasy Asclepiadoideae (Apocynaceae) Sigrid LIEDE & Ulrich MEVE Dept. of Plant Systematics, University of Bayreuth, 95440 Bayreuth, Germany. [email protected] ABSTRACT KEY WORDS In the genus Pentatropis, P. madagascariensis is recognized as a subspecies of Apocynaceae, P. nivalis. In the stem-succulent species of Cynanchum, C. bekinolense is Asclepiadoideae, considered a northern subspecies of C. gerrardii. All species of Folotsia, Pentatropis, Cynanchum, Karimbolea and Platykeleba, as well as the Malagasy species of Sarcostemma, Madagascar. are formally transferred to Cynanchum. RÉSUMÉ Nouvelles combinaisons et nouveaux noms dans les Asclepiadoideae (Apocynaceae) de Madagascar. MOTS CLÉS Pentatropis madagascariensis est transféré dans P. nivalis, au rang de sous- Apocynaceae, espèce. Parmi les espèces de Cynanchum à tiges succulentes, C. bekinolense est Asclepiadoideae, considéré comme une sous-espèce septentrionale de C. gerrardii. Toutes les Pentatropis, Cynanchum, espèces de Folotsia, Karimbolea et Platykeleba, de même que les espèces Madagascar. malgaches de Sarcostemma sont transférées dans le genre Cynanchum. In the course of preparing the treatment of Decne., which has often been included in Asclepiadeae (Apocynaceae – Asclepiadoideae) P. nivalis (J.F. Gmel.) D.V. Field & J.R.I. Wood, for Flora of Madagascar (Liede, in press), two a species distributed from East Africa to India. geographically restricted taxa were found to The Malagasy plants are generally smaller and resemble very closely widespread, variable taxa, more tender than the mainland plants and thus but differering in one or a few minor but con- easy to recognize. In floral characters, though, stant characters. They are considered subspecies they are almost indistinguishable. The second of their widespread relatives. The first of these plant is a member of the equally widespread taxa is the Madagascan representative of the Cynanchum gerrardii complex, described as genus Pentatropis R. Br., P. madagascariense C. bekinolense Choux. The plants of northern ADANSONIA, sér. 3 • 2001 • 23 (2) : 347-351 © Publications Scientifiques du Muséum national d’Histoire naturelle, Paris. 347 Liede S. & Meve U. Madagascar and the Comores are more slender c. 8 mm long, abaxially and adaxially purple, api- than those from southern Madagascar, mainland cally yellow; adaxially densely covered with Africa and Arabia, the fruits are keeled, the stami- c. 0.1 mm long trichomes; lobes 3 mm wide, tri- nal corona parts are not more succulent than the angular, incurved. Corona of free staminal parts interstaminal ones and the pedicels are character- attached to the back of the stamens, shorter than istically curved. In general structure, though, the the gynostegium, carinate, glabrous. Gyno- close relationship of C. bekinolense and C. ger- stegium c. 1.5 mm high, 0.8 mm diam., sessile. rardii is unmistakable. Anthers longer than broad, rectangular, abaxially A molecular analysis using chloroplast spacers planar. Anther wings 1.5 mm long, following the and ITS (Liede & Täuber submitted, Liede & basal lateral margin of the anther; consisting of Kunze, in prep.) has shown beyond doubt that all proximal and distal ridge, space between the stem-succulent cynanchoid taxa are mono- ridges almost glabrous. Connective appendages phyletic and nested within the Malagasy clade of 0.2 mm long, 0.3 mm wide, ovate, narrower than Cynanchum. Thus, all small stem-succulent gen- the anther, slightly inflexed. Pollinarium: corpus- era and the larger genus Sarcostemma s.str. need culum 0.16 mm long, about as long as broad, to be included in Cynanchum, and numerous ovoid; caudicles 0.06 mm long, cylindrical, name changes are necessary. The former genus straight, declinate; pollinia subapically attached Sarcostemma s.str. comprises a species complex in to the caudicles, 0.2 mm long, 0.12 mm wide, which delimitation of species and subspecies is ovate in cross-section, ovoid. Stylar head green, still a matter of debate. A detailed study using c. 0.8 mm diam., 0.6 mm high, upper part RAPDs is being carried out in our lab to clarify 0.4 mm high, depressed-conical. Follicles the structure of this complex. Before this study is c. 55 mm long, 6 mm diam., obclavate, apically completed, new combinations for all published strongly beaked, wingless, light brown. Seeds Sarcostemma names would be premature; there- ovate, c. 5.5 mm long, 2.7 mm wide, seta and fore, only the name changes necessary for the aseta side sculptured with longitudinal ridges, Flora of Madagascar treatment are proposed here. marginally with slightly emarginate, 0.15 mm wide wing; coma c. 20 mm long. Chromosome number: 2n=22 (Liede & Conrad Pentatropis nivalis (J.F. Gmel.) D.V. Field & 2749). J.R.I. Wood subsp. madagascariensis (Decne.) Liede & Meve, comb. et stat. nov. DISTRIBUTION AND HABITAT. — Madagascar, prov. Antsiranana, Fiarantsoa, Mahajanga, Pentatropis madagascariensis Decne. in DC., Prodr. 8: Toliara; sea level to 200 m, on sand and rocks 536 (1844). — Type: Bojer s.n., Madagascar, in close to the sea, rocky places in dry forest. arenosis ad sinum St. Augustin or. occident.” (holo-, P!). FLOWERING TIME. — All year. VERNACULAR NAME. — Tsinainkibo (Toliara; Plants ascending, twining. Shoots herbaceous, used medicinally fide Sussman 324). sparsely pubescent along a single line with 0.18- 0.2 mm long trichomes, glabrescent. Pseudo- SPECIMENS EXAMINED.—MADAGASCAR: Bojer s.n., stipules absent. Leaves with 2-3 mm long petiole; in sinus St. Augustin (P), type; Bosser 27, colleters absent; leaf blades herbaceous, 12- Lambomakondro, 17 May 1951 (P); Croat 30925, forest of Besaka Zombitzy, 730-750 m, 7 Feb. 1975 27 mm long, 7-9 mm wide, elliptic, basally (MO); Croat 31397, 2 km W of Ampanihy, SW of rounded, apically obtuse, adaxially isolatedly cov- Ampanihy on road to Androka between Ampanihy ered with 0.2-0.25 mm long trichomes restricted and PK 10, 150-200 m, 16 Feb. 1975 (MO); D’Arcy to the midvein and the margins, abaxially & Rakotozafy 15462, 5 km N of Bealandra, 17 May glabrous. Inflorescences sessile, 2-3-flowered, all 1983 (MO); Decary 3349, Ambovombé, 5 Dec. 1924 (P); Decary 8529, Ambovombé, 3 Jan. 1932 (TAN), flowers open synchronously. Flowers with 10- Decary 9529, Ambovombé, 3 Jan. 1932 (P); Descoings 25 mm long pedicels. Calyx basally fused; lobes 1924, Dec. 1956 (P); Grandidier s.n., Manambé à 2 mm long, triangular. Corolla basally fused, Mourondave, Feb. 1869 (P); Humbert & Perrier de la 348 ADANSONIA, sér. 3 • 2001 • 23 (2) Asclepiadoideae (Apocynaceae) from Madagascar Bâthie 2492, environs de Tuléar, Delta de Fiherenana, ulate, basally fused; 1.5-2 mm long, abaxially and 2-10 m, Sep. 1924 (P); Liede & Conrad 2749, Fort adaxially yellow, purple along the main nerves; Dauphin, seaside, ± 5 m, 17 Feb. 1990 (P, TAN, UBT); Peltier & Peltier 3131, s.loc. (P); Peltier & lobes 0.8-1 mm wide, horizontal to decurved, Peltier 4917, Belahamy, 26 Jan. 1964 (P); Perrier de la oblong to triangular, apically acute. Gynostegial Bâthie 1233, Amboanio près de Mahajanga, Feb. 1901 corona yellow, tubular, 1-1.2 mm high, equalling (P); Perrier de la Bâthie 11697, baie de Bombetoke, the gynostegium in height, consisting of staminal Oct. 1907 (P); Poisson 97, Belabaka, 8 Jan. 1921 (P); and interstaminal corona parts fused for 1/4 to Rakotozafy 779, Tuléar, col sale, près du terrain d’avia- tion, Apr. 1968 (P); Rakotozafy 1524, Ramena à l’est 1/2 of total corona length, only staminal corona de Diégo-Suarez, Oct. 1975 (TAN); Sussman 324, parts differentiated. Staminal corona parts near Analafaly, 40 km NE of Betioky Andrekerere, appressed to the back of the anthers, apically 17 Oct. 1987 (MO). erect, adaxially with a basal protuberance corre- sponding to the filament; lobes of staminal The genus Pentatropis is very widespread along corona parts laminar, oblong, with straight mar- the West and East African, as well as the Asian gins. Gynostegium 1.5-1.7 mm high, 1.2- coast as far as Australia. While specific and sub- 1.3 mm diam., sessile. Stamens with filament specific delimitation is not well understood, the 0.25-0.35 mm long; anthers longer than broad; Malagasy material matches P. nivalis (J.F. Gmelin) rectangular, abaxially planar to convex. Anther D.V. Field & J.R.I. Wood from East Africa in flo- wings 0.7-0.8 mm long, extending beyond the ral structure, but the plants are easily distin- anther proper, forming a basal arch; adjacent guished by their small, elliptic leaves, the anther wings divergent towards the base, in the generally much more tender habit and the same plane as the anther. Connective appendages slightly smaller size of the flowers. As these char- 0.5-0.6 mm long, 0.6-0.75 mm wide, widely acters are restricted to Malagasy material, recog- ovate, equalling the stamen in width, strongly nition on subspecific level is appropriate as inflexed. Pollinarium: corpusculum 0.25- compared to species concepts applied throughout 0.28 mm long; caudicles 0.12-0.14 mm long, the subfamily. cylindrical, straight, declinate, thickened at the insertion of the pollinium; pollinia 0.3-0.35 mm long, 0.17-0.2 mm wide, ovate in cross-section, Cynanchum gerrardii (Harvey) Liede subsp. ovoid, laterally attached to the caudicles. Stylar bekinolense (Choux) Liede & Meve, comb. et head 1.2-1.4 mm diam., 0.5-0.6 mm high; upper stat. nov. part 0.25-0.3 mm high, umbonate to tabular. Follicles one per flower, pendant, c. 70 mm long, Cynanchum bekinolense Choux, Ann. Inst. Bot.-Géol. 3.5 mm diam., obclavate, obtusely deltate in Colon. Marseille, sér. 3, 2: 311 (1914). — Type: cross-section, apically shortly beaked, keeled, Perrier de la Bâthie 11740 (holo-, P!). medium brown, glabrous. Seeds 3-3.5 mm long, Plants twining. Subterranean organs unknown. 1.5-1.8 mm wide, pyriform, medium brown, seta Shoots semi-succulent, finely striate, obscurely and aseta side regularly papillose and with regu- glaucous, glabrous; internodes 1-1.5 mm diam.