Arisaema ringens (Thunb.) Schott

Plants dioecious. Tuber depressed globose, 2–5cm in diam. Cataphylls greenish to purplish. Leaves 2; petiole greenish and unmarked, 15–35cm, proximal 1/3 sheathing into pseudostem; leaf blade 3-foliolate; leaflets sessile, glaucous abaxially, green adaxially, margin entire, apex long acuminate with a tail ca. 2cm; central leaflet ovate-lanceolate to rhombicelliptic, 16–22 × more than 10cm, base cuneate; lateral leaflets obliquely ovate, 15–18 × 10–13cm, apex filiform-caudate. Peduncle greenish, unmarked, shorter than petioles, to 25cm. Spathe yellowish green to green; tube yellowish green to green outside, purplish red with white or pale yellowish green striations inside, cylindric, gradually opening to an auriculate throat, 3–3.5 × 1–2cm; limb concave and incurved, saccate, apex caudate. Spadix unisexual; female zone conic, ca. 1.8 × 1.2cm; ovary greenish, obovoid; stigma subsessile, pilose; male zone sessile, cylindric, ca. 1.5cm × 8mm; synandria subsessile; anthers 2 or 3; thecae globose, dehiscing by an apical pore. Appendix erect, white, narrowly conic, 2–6cm × 5–10mm, base truncate and stipitate, apex obtuse; stipe 3–10mm. Infructescence erect. 2n = 28.