Arisaema peninsulae Nakai

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