Hygrophila R.Br.

2 species in Aust. (1 native, 1 naturalized); Qld, NSW, WA, NT

*Hygrophila costata Nees

Herb to 2 m high. Stems often reddish, 4-angles, lower nodes swollen. Leaves lanceolate to elliptic, 3.5–18 cm long, up to 5 cm wide. Margins entire, undulate. Petiole to 3.5 cm long. Inflorescence axillary, flowers sessile in clusters of 3 or 4. Corolla white, 5–10 mm long. Capsule 8–13 mm long, glabrous. Waterways in disturbed areas. Introd. from Central and S. America