Arisaema lobatum Engl.

Plants dioecious. Tuber bluish green outside, globose, 2–4cm in diam. Cataphylls 3, brown, usually with reddish spots, 15–20cm, apex acute or obtuse. Leaves 1 or 2; petiole greenish or olive-green with purple spots, 17–35cm, proximal 1/3–1/2 sheathing into pseudostem; leaf blade 3-foliolate, pale greenish with pink raised veins abaxially, green with pale green veins adaxially; central leaflet with petiolule 1.5–5cm, blade oblong or elliptic, 8–22 × 4–10cm, base narrowly attenuate or obtuse, apex acuminate; lateral leaflets sessile, oblique, oblong, 3–23 × 2–8cm, outer base auriculate and rounded. Inflorescence unfolded before leaves; peduncle nearly as long as petiole, but usually shorter. Spathe pale purplish or pale olive-green with purple stripes; tube funnelform, 4–7 × 1–2.5cm, throat not auriculate, obliquely truncate, narrowly recurved or not; limb incurved or nearly erect, usually with whitish stripes inside, broadly lanceolate or ovate, 4–7 × 2.5–3cm, constricted to base, apex acuminate, usually with a tail 3–5cm. Spadix unisexual; female zone cylindric or subglobose, 1–2cm; ovary green, obovoid; style short; stigma disciform; male zone cylindric, 1.5–2.5cm; synandria lax; anthers 2 or 3, stipitate; thecae violet, ovoid, dehiscing by apical pore. Appendix erect, pale green to whitish green, cylindric, middle slightly constricted, base truncate and stipitate, apex obtuse; stipe 6–8 mm. Infructescence nodding. 2n = 28*, 56*, 84*.