五叶山珠南星 wu ye shan zhu nan xing

Type: China. Yunnan: Lijiang, Hutiaoxia (虎跳峡, "Tiger Leaping Gorge"), 1860 m, 20 Jun 1995, J. Murata, X. Cheng, H. Takahashi, J. Ohno & H. Murata s.n. (holotype, TI).

Haec species quoad inflorescentiam eadem ac Arisaema yunnanense Buchet est, sed ab eo foliis 5-foliolatis et chromosomatum numero diploideo 2n = 24 differt.

Plants dioecious, 10-40 cm tall. Tuber depressed globose, 1-5 cm in diam., with some tubercles around. Leaves 1 or 2; petiole 10-45 cm, proximal 6-28 cm forming pseudostem, usually greenish, unspotted; leaf blade palmately 5-foliolate; leaflets green, narrowly elliptic to elliptic, 4-13.5 × 1-7 cm, base cuneate, margin entire, apex acuminate. Inflorescence unfolding after leaf blade; peduncle longer than petioles. Spathe green, with longitudinal white lines; tube 2-2.5 × 1-1.4 cm, throat margin obliquely truncate, not auriculate; limb arching from base, ovate, ca. 5 × 3.5 cm, apex acuminate. Spadix unisexual; female zone conic, ca. 1.5 cm; ovary green, bottle-shaped; ovules 3, basal; style ca. 0.5 mm; stigma depressed globose; male zone pale green, pyramidal, 1.5-2 cm, base 3-5 mm in diam.; synandria of 2 or 3 stamens; thecae violet or cream-colored, globose, opening by apical pore; pollen verrucate between conic spines. Appendix recurved outward or downward, green, narrowly conic, 3.5-6 cm, base 2-2.5 mm in diam. Berries red, subcylindric. Seeds 2 or 3, ovoid-globose. Fl. May-Jul, mature fr. Aug-Sep. 2n = 24*.

● Pinus-Quercus forests, grassy slopes, roadsides, thickets; 1800-2100 m. NC and NW Yunnan (Lijiang, Wuding, Yuanmou, Zhongdian).

This species is considered to be the diploid ancestor of Arisaema yunnanense, which is tetraploid, with 2n = 48 chromosomes. It also differs from A. yunnanense in having always quinate leaves.