Tuber 1-2 cm in diameter, spherical. Stems to 30 cm or more. Leaves 6-9 per plant; petiole flattened; lamina 5-17 × 2-6 cm, oblong, floating; base cordate; apex obtuse, apiculate. Spikes 3-12 cm, forked; peduncle usually swollen above. Flowers arranged all round the rhachis, the spikes characteristically tapering above; perianth segments 2, yellow. Stamens usually 6. Carpels 3-5. Follicles 3 mm, brownish-yellow.