28. Arisaema vexillatum H. Hara & H. Ohashi, J. Jap. Bot. 48: 99. 1973.
细腰南星 xi yao nan xing
Plants dioecious. Tuber brown outside, white inside, depressed globose, 1.5-3 cm in diam. Cataphylls 2 or 3, pink to purple, to 8 cm, membranous. Leaf solitary; petiole greenish, not spotted, terete, 15-18 cm, basal part forming pseudostem, smooth, not verrucose; leaf blade 3-foliolate; leaflets subsessile, green usually with bluish margins; central leaflet broadly obovate or rhombic, 4-5(-11) × 4-5(-10.5) cm, apex abruptly acuminate or rounded with an acumen 2-3 mm; lateral leaflets larger than central one, ovate or rhombic, 8-9(-15) × 4(-9) cm, base cuneate, slightly oblique, apex acuminate. Peduncle greenish as petiole, shorter than petioles, 6-10 cm. Spathe tube dark purple with whitish longitudinal lines, cylindric, 4.5-5 × 1.5-2 cm, throat obliquely truncate, slightly recurved, not auriculate, inside distinctly lamellate, throat abruptly constricted into an intermediate zone 1.5-2 cm wide; limb above intermediate zone strongly dilated, reniform or subcordate, 3-5 × 4-7 cm, purple with whitish reticulate networks, apex rounded with a tubular tail 3-4 cm. Spadix unisexual; female zone conic, ca. 1.2 cm × 8 mm; ovary green; stigma subsessile, dark purple, ovoid; male zone cylindric, ca. 2 cm × 5 mm; synandria of 3 or 4 stamens; connected filaments purple, distinct; anthers yellowish, globose, dehiscing by horseshoe-shaped slit. Appendix purple, flagellate, recurved distally following spathe limb, 9-11 cm, base swollen, 4-5 mm in diam., truncate and stipitate; stipe 8-10 mm. Fl. Jun.
Thickets, grasslands on slopes; 3500-3700 m. S Xizang [E Nepal].