A New Tassadia (Apocynaceae, Asclepiadoideae) from Bolivia and Brazil WI D. Stevens Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A.
[email protected] Tassadia capitata, from Santa Cruz,Bolivia, and Para, Brazil, is described and illus-trated. This new species is most closely related toT guianensis Decaisne, and the two species aresomewhat intermediate between Tassadia and Sten-omneria. Key words: Apocynaceae. Asclepiadoideae. Bo-livia, Brazil, Stenomeria, 7issadia. Tassadia I)ecaisne is a genus of about 25 speciesof tropical and subtropical South America. with onespecies, T oborata D)ecaisne. ranging through Cen-tral America to Veracruz, Mexico. Tassadia belongsto the tribe Asclepiadeae and is most closely re-lated to the genus Stenomeria Turcz. The two gen-era share, in particular, an unusual arrangement ofthe inflorescences. The true inflorescence is an ex-tra-axillary cnime, which is the normal inflorescenceof the Asclepiadoideae. However, these sessile ornearly sessile, congested cymes are mostly ar-ranged along leafless axillarv branches: cymes as-sociated with leafy nodes are also occasionally pro-duced. These inflorescences have been describedas thyrses or pleiothyrses (Fontella, 1977: Morillo,1990), but those terms refer to mixed inflorescencesin which the primary axes are paniculate and theultimate axes cymnose (Jackson, 1928). ,iede andWeberling (1995) also considered the leaflessbranches to be inflorescences and erroneously comn-pared them with the true, extra-axillary inflores-cences of 7~vlophora, which are superficially similar.Liede and Meve (2001) repeated the error in con-sidering the inflorescences of 7Tssadia to be "lax."Stenomeria differs from Tassadia in having rostrateand glabrous style apices, strongly contorted corollalobes, and slender and smniietrical follicles. InTassadia, only this new species and 7: guianensishave elongate style apices and in both cases theyare penicillate, the corolla lobes are slightly to notat all contorted, and the follicles, when known, tendto be broad and/or aslymmetrical.NOVON 12: 408-110. 2002.Tassadia capitata W. I). Stevens, sp. nov. TYPE: Bolivia. Santa Cruz. Velasco Prov.: Parque Na-cional Noel Kempff Mercado, Arroyo (Las IAn-dras, a 15 km al N del empalme hacia el ase-rradero Chore,. bosque inundado temporalmente, sierpreverde, 14�24' 18"S, 61�08'40"W, 150 im. 10 Oct. 1996. . M. Carrin, R. Guillen, M. Ganrizri, P. Sol:z, .1. Hiufrman & L Sauedo 360) (holotype, MO; isotylp, USZ). Figure I A-I). A Tass.tadia guiainensi I)ecaisne apice styli capitalo dig-noscenda. Twining (to right) vine, lower parts unknown,stems densely puberulent with curved, multicellu-lar. red-tipped hairs 0.2-0.4 mnin long: sap white.Ieaves opposite, without pseudostipules, blade3.6-7.5 X 1.7-1.2 nim, elliptic, apex abruptly acu-iniate, base acute to obtuse or nearly rounded, gla-brous above except with a line of hairs on midrib.densely and uniformly puberulent below. lateralveins 4 to 7, colleters 2; petiole 4-8 mm long. pu-berulent. Inflorescence extra-axillary. 1 per node,congested-cymose. arranged on leafless or nearlyleafless axillary or terminal branches with the ap-pearance of inflorescences or occasionally with iso-lated inflorescences at leafy nodes, peduncle absentto 1 mmn long, pedicel 0.5-1.2 nun long, bracts 0.6-0.7 X 0.4-0.7 nun, ovate; calyx divided to base,with 0-2 colleters per sinus, lobes ovate to lance-olate with acute to obtuse tips. 0.8-1.4 X 0.5-0.9mnn. apparently green, glabrous to sparsely puber-ulent along midrib outside, glabrous inside: corollacampnanulate at base, aestivation weakly contortedand dextrorse, white with a yellow or green tint,tube 0.7-1.5 unm long, glabrous outside, barbateinside with glassy, unicellular hairs ca. 0.1 mtnlong, lobes narrowly lanceolate with acute tips.erect. 2.6-3.6 nin long, 0.8-0.9 mm wide at base.glabrous outside, inside with margins densely pu-berulent with white, unicellular hairs ca. 0.05 inilong: androeciunm and gynoecium entirely fused andforming a short-stipitate gynostegium; corona gy-nostegial. adnate to gynostegium at base, of 5 freelobes opposite the anthers. these rounlded and with
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