Tubers ovate to elongate, to 4 cm long. Leaves submerged, rarely floating. Submerged leaves: petiole to 30 cm long; blade narrowly to broadly elliptic, 10–50 cm long, 2–5 cm wide; base tapering gradually into petiole, sometimes asymmetric; margins sometimes slightly undulate; apex blunt-cuneate or obtuse; veins 5–9; lacunae absent or to 2 (–4) rows on either side of midvein. Peduncle to c. 90 cm long, broadening at inflorescence base. Spathe to 1.5 cm long, caducous. Inflorescence emergent or floating, single, to c. 15 cm long, yellow. Flowers tightly to widely-spaced, turned in all directions, bisexual. Perianth segments 2, cuneate, 1–1.4 mm long, yellow, 1-veined. Stamens 6. Carpels (2–) 3 (–6). Fruiting carpels rounded, 2.5–5.8 mm long, 1.8–5.0 mm wide, thick-coated; beak mostly lateral, occasionally terminal, to 1.5 mm long. Seeds 2–5 per fruit, elliptic, 1.2–3.2 (–4.2) mm long, 0.5–1.1 (–1.6) mm wide; testa single, closely adhering to embryo or very thin.
Home