Limnophyton obtusifolium (L.) Miq.

Annual, erect, 60-90 cm tall herb. Leaves broadly ovate, sagittate, with spreading, acute triangular lobes, 15-30 cm long, pellucid-punctate, obtuse or emarginate at the apex; petiole 30-80 cm long, triangular, spongy. Peduncle as long as the petioles, triangular. Flowers 5-10 in each whorl, c. 1 cm across; pedicels 2.5-5 cm long, reflexed and thickened in fruit; bracts triangular-lanceolate, 1.5-2.5 cm long, c. 1 cm broad, bracteoles minute. Sepals ovate-elliptic, 4-6 mm long, 2-3.5 mm broad, obtuse, green. Petals delicate, obovate-elliptic, larger than the sepals. Stamens with c. 3 mm long, basally flattened and thickened filaments; anthers oblong. Achenes obovate, minutely stipitate, 4-6 (-8) mm long, 3-4 mm broad, reticulately ribbed, shortly beaked.

Distribution: Far east Asia to Madagascar and topical Africa through Indo-Pakistan subcontinent and Sri Lanka (Ceylon).

Fl. Per.: July-September.

obtusifolium: with obtuse leaves

Annual or perennial (semi-)aquatic herb, up to 1.5 m tall. Rhizome small; roots fibrous and spongy. Leaves emergent, erect; petiole up to 50 cm long, 3-angular in cross-section. Lamina sagittate, mostly hairless, with scattered pellucid dots, wider than the length ot the midrib and basal lobes as long or longer than the mid rib; veins 13-17, 3-4 pairs arising from the base, arching to the leaf apex, the others curving down towards the tips of the lobes. Inflorescence on a stout peduncle 0.3-1 m long, branched with 4-7 whorls of flowers. Flowers bisexual or some male in the basal whorls, with greenish petals and white petals. Fruit with up to 30 carpels, forming a globose head, 10-12 mm in diameter.

Widespread in tropical and subtropical Africa, Madagascar, India, Sri Lanka, Indochina and Malaysia

Limnophyton obtusifolium est une espèce de plante herbacée de la famille des Alismataceae. On la trouve en Afrique et en Asie tropicale.

Limnophyton obtusifolium trong tiếng Việt thường được biết đến với tên gọi hồ thảo là một loài thực vật có hoa trong họ Alismataceae. Loài này được (L.) Miq. mô tả khoa học đầu tiên năm 1856.