Acanthaceae

Hygrophila polysperma

Common Names: East Indian hygrophila

Plant Form: Low growing aquatic or emergent herb. Size: Up to 1 m tall. Stem: Round and up to 2 m long when underwater. Square and slightly hairy when above water. Leaves: Bright green, brown or reddish. Up to 8 cm long. Oblong or oval shaped with pointy tips, and with a thin cover of fine white hairs. Long and narrower underwater, rounder above water. Flowers: White or bluish-white, tubular with 5 fused petals. About 5 mm across. In between stems and leaves of upper stems. Fruit and Seeds: Narrow capsule about 6 mm long which splits along length to release 15-30 seeds which are covered in hairs. Habitat: Lakes, dams, ponds, wetlands. Distinguishing Features: Can be confused with native Willow hygro (Hygrophila angustifolia) but differs mainly by growing while submerged.