细齿南星 xi chi nan xing

Arisaema angustatum Franchet & Savatier var. peninsulae (Nakai) Nakai.

Tuber depressed globose, 1.5-5.5 cm in diam. Cataphylls 3, brownish with purple spots, 3-10 cm. Leaves 2; petiole 35-93 cm; pseudostem (sheathing part) 29-77 cm; leaf blade pedate; leaflets 7-17(-23); rachis well developed between terminal and lateral ones, and between lateral ones; leaflets narrowly elliptic, obovate-lanceolate, or ovate-oblong, base cuneate, margin entire or serrate, apex acuminate; central leaflet with petiolule 1-4 cm, blade 9-18 × 3.5-9 cm, gradually smaller outward; lateral leaflets remote from central one for 1-4 cm, shortly petiolulate or sessile, ca. as large as central one; outer lateral leaflets sessile and much smaller than central leaflet. Peduncle erect, 30-80 cm. Spathe usually green with white stripes, or purplish to dark purple with whitish stripes; tube 5-8 × ca. 1.5 cm, throat obliquely truncate, scarcely recurved; limb incurved, usually green, or dark purple, oblong, 5-6 × 4-5 cm, apex acuminate. Spadix unisexual; female zone 1.5-3 cm × 5-7 mm; ovaries dense, narrowly ovoid; style short; stigma disciform; male zone 1-1.5 cm; synandria dense, sessile; anthers 2 or 3; thecae globose, dehiscing by apical pores. Appendix erect, cylindric, 3.5-4 cm × 3-6 mm, base truncate and stipitate, apex obtuse; stipe 4-5 mm. Berries reddish yellow, ovoid-globose, ca. 8 × 7 mm. Seeds 2 or 3, yellow-brown, ca. 4 mm in diam., rugose. Fl. May-Jun, mature fr. Sep.

Forests; below 500 m. Heilongjiang, Henan, Jilin [Japan, Korea].

Chinese records of Arisaema serratum (Thunberg) Schott (e.g., in FRPS 13(2): 179. 1979) are referable to A. peninsulae.