Arisaema utile Hook.f. ex Schott

Plants dioecious. Tuber depressed globose, 3–10cm in diam., with small tubercles. Cataphylls to 9cm, membranous. Leaf solitary; petiole green with dark purple spots, 20–40cm, proximal 1/3 sheathing into pseudostem; leaf blade 3-foliolate; leaflets sessile or subsessile, green with reddish margin; veins raised, often reddish abaxially; central leaflet broadly rhombic or ovate-rhombic, sometimes broader than long, 7–15 × 6–11cm, base broadly cuneate, apex acuminate; lateral leaflets obliquely ovate, 11–14 × 7–9cm, base rounded to subtruncate, apex acuminate. Peduncle shorter than petioles, 20–22cm. Spathe tube purplish brown with longitudinal whitish lines, cylindric, 4–5 × 1.5–2cm, longitudinally lamellate inside, throat margins slightly recurved; limb strongly incurved, dark purple with white longitudinal and reticulate lines (at margin), obovate, 7–8 × 3–5cm, apex acuminate. Spadix unisexual; female zone conic, 2.6–6cm; ovary green, obovoid; stigma subsessile, dark purple; male zone 1.5–2cm × ca. 4mm; synandria of 2–5 stamens; connected filaments distinct, 0.5–1mm; anther dehiscing by horseshoe-shaped slit. Appendix brown, flagelliform, 11–20cm, thickened toward base 5–15 mm wide, base truncate and stipitate.