滇南南星 dian nan nan xing

Tuber globose, 1-2 cm in diam. Cataphylls green, acute. Leaf 1; petiole green, proximally sheathing into pseudostem; leaf blade 3-foliolate; leaflets glaucous abaxially, green adaxially; central leaflet with petiolule ca. 15 mm, blade ovate or ovate-oblong, 8-10 × 2.8-6 cm, base obtuse, apex abruptly acuminate; lateral leaflets with petiolule 3-5 mm, blade ovate-lanceolate, 9-10 × 4.8-5 cm, base rounded, oblique, apex acuminate. Peduncle as long as petioles, slender. Spathe small, ca. 6.5 cm in total; tube pale green, funnelform, ca. 2.8 cm, throat ca. 1.5 cm in diam., margins obliquely truncate, not auriculate; limb erect, dark green, ovate-lanceolate, ca. 3 × 1.5 cm, apex acuminate with a short tail at tip, base slightly constricted, with a white ca. 5 mm high basal zone. Spadix unisexual. Male spadix slender; male flowers sparse; synandria of 2-4 stamens, subsessile; thecae subglobose, opening by an apical slit; appendix erect, ca. 2.2 cm, slender, with several scattered, short, subulate neuter flowers from base to apex; neuter flowers less than 1 mm. Female spadix unknown. Fl. May.

Tropical forests; ca. 800 m. S Yunnan (Jinghong, Simao) [Vietnam].

Chinese records of Arisaema balansae Engler (H. Li, Bull. Bot. Res., Harbin 8(3): 99. 1988) and A. ramulosum Alderwerelt van Rosenburgh (Gusman & Gusman, Gen. Arisaema, 220. 2006; Gusman, Aroideana 30: 43. 2007, p.p., as to Vietnamese element; Yin & Gusman, Aroideana 31: 98-100. 2008) are referable to A. austroyunnanense. In the treatment of Arisaema in Flora Malesiana (Murata, in press), A. laminatum will be recognized in a broad sense including A. ramulosum and A. austroyunnanense. Gusman et al. (loc. cit.) separated A. ramulosum from A. laminatum; they did not refer to A. austroyunnanense, but it may have been included in their concept of A. ramulosum. In the present treatment, however, it seems best to recognize A. austroyunnanense as a separate species because it has been known by a single specimen (the type) and we cannot consider variation in China. Gusman et al. (loc. cit.) also reported A. barbatum Buchet (Notul. Syst. (Paris) 1: 366. 1911) from S Yunnan (Xishuangbanna) by presenting a photograph. However, this record requires confirmation because it does not seem to fit typical A. barbatum, from Java, and no herbarium specimen is available at present.