Plants dioecious. Tuber nearly globose, 1-3 cm in diam. Cataphylls 2 or 3, to 17 cm. Leaves 1 or 2; petiole green, unmarked, 16-50 cm, proximal 1/4-1/2 sheathing into pseudostem; leaf blade pedate; leaflets 5-9, pale greenish abaxially, green adaxially, linear to narrowly lanceolate, sessile; central leaflet 15-20 × 1-1.5 cm; lateral leaflets gradually smaller and shorter toward outermost, outermost ones 2-3 cm × 1-5 mm. Peduncle green, 10-50 cm, shorter or longer than petioles. Spathe yellowish green, 5-15 cm in total; tube narrowly cylindric, 2.2-6 cm × 4-20 mm, throat obliquely truncate, not recurved; limb suberect, ovate to narrowly ovate, 4-7 × 1-2 cm, apex acuminate. Spadix unisexual; female zone 1.2-2.5 cm; ovary whitish green, obovoid; ovules 3; stigma with short stipe; male zone cylindric, 1.8-3 cm, densely flowered; synandria sessile, consisting of 2-4 anthers, each with 2 thecae dehiscing by apical pores. Appendix sessile, sigmoid or simply curved forward, yellowish green to violet, 4-17 cm × 2.5-4 mm. Fl. Apr-Jun.