Hydrocharis laevigata

Leaves with lamina elliptic to widely elliptic, rarely obovate or reniform, (5–)20–50(-70 mm long, (3–)8–40(–65) mm wide; leaf apex usually rounded, occasionally acute or mucronate, base cuneate to truncate, rarely cordate; with a thick layer of aerenchymous tissue on the underside; petioles of aerial leaves 26–270 mm long, not inflated, petioles of floating leaves 5–85 mm long, sometimes inflated; stipules to 22 mm long, sheathing the developing apex. Male spathes containing up to 11 flowers; peduncles to c. 25 mm long; pedicels to c. 43 mm long;  sepals narrowly to widely elliptic; petals flowers greenish-white to yellowish; stamens 6 (very rarely up to 9), in 2 (3) whorls; staminal column up to 2 mm long at anthesis; free filaments 0.3–1.3 mm long. Female spathe containing up to 3 greenish-white flowers; peduncle c. 2 mm long or absent; pedicels to 40 mm long at anthesis, becoming somewhat longer in fruit; sepals greenish-white, spreading; petals usually absent, but sometimes up to 3 and 1–5.5 mm long; staminodes present; ovary  of 3–6 carpels (6–12 stigmas), without dissepiments. Fruit ellipsoid to obovoid, 1.7–5 mm diam., containing up to c. 100 seeds. Seeds 0.8–1.2 mm long, 0.6–0.8 mm wide, trichomes 0.1–0.2 mm long.