Arisaema amurense Maxim.

Tuber depressed globose, 6–7cm in diam. Leaves 2(or 3); petiole (5–)7–30cm, proximal 3/4 sheathing and forming pseudostem; leaf blade 3-foliolate or pedately 5-foliolate; rachis between leaflets 0–6cm; leaflets sometimes covered with fine whitish marks, obovate to narrowly oblong, 7–11 × 4–7cm, base cuneate, margin entire or serrate, occasionally denticulate, apex acute; central leaflet with petiolule 5–25mm; lateral leaflets remote from central one for 1–30mm; outermost leaflets sessile, 9–15cm, oblique, cuneate at base on inner side, auriculate or rounded on outer side. Peduncle shorter than petioles. Spathe greenish to dark purple, usually with pale purplish stripes; tube funnelform to cylindric, ca. 5cm, ca. 2cm in diam. at throat, throat obliquely truncate, not auriculate; limb ovatelanceolate to oblong, 3–4cm, apex acuminate. Spadix unisexual; female zone subconic, ca. 2cm, ca. 1cm in diam. at base; ovary obovoid; ovules 4; stigma spherical; male zone cylindric, ca. 2cm × 2–3mm; synandria lax, nearly sessile; anthers 2 or 3; thecae globose, dehiscing by apical pores. Appendix stipitate, erect, cylindric and robust, 3–5.5cm × 4–5(–7)mm, base truncate, apex obtuse. Berries red, narrowly conic. Seeds 4, red, ovoid, smooth. 2n = 28, 56.