Arisaema calcareum H.Li

Plants deciduous, to 120cm tall and 60cm wide. Tuber subglobose or cylindric, 2.5–6cm in diam. Cataphylls 3, flesh-colored, longitudinally striped and mottled, lanceolate, 2–40cm, apex obtuse for shortest. Leaves 2, subopposite; petiole light green, plain or stained with purple, to 60cm, proximal part to 45cm sheathing into pseudostem; leaf blade 3-foliolate; leaflets abaxially paler, sometimes flushed carmine, adaxially green and with impressed, thin, and light green veins and a broad, white-green central midvein, margins entire, base convex and petiolulate, apex acuminate; central leaflet with petiolule to 4cm, blade subrhombic, shorter than lateral ones, 20–50 × 10–25cm, base cuneate; lateral leaflets with petiolule to 2cm, blade ovate, 20–55 × 10–25cm. Inflorescence unisexual, emerging when leaves unfold and held nearly at foliage level; peduncle pale green, shorter than petioles, 10–20 × ca. 1cm. Spathe tube green with white stripes, basally white, cylindric, ca. 7 × 1.5cm, throat not expanded; limb curved forward, green with conspicuous white stripes and a white spot at throat level, oblong-lanceolate, ca. 6 × 2.5 cm, apex long acuminate. Spadix: ovaries congested, ovoid, ca. 2.5 × 2mm; ovules ca. 2; stigma penicillate, borne on a short style; male flowers unknown; appendix slightly exserted from tube, erect, pale green, cylindric, 6–8 cm × ca. 5 mm, slightly narrowed to both ends, base with scattered hornlike projections (these curved, 3–5mm, often brown and bifid at apex), apex rounded. Fruiting spike upright.