Asystasia gangetica(L.) T. Andersonssp. gangetica

Tracheophyta: Angiospermae: Eudicot: Asterid: Lamiales: Acanthaceae

Non-native

A herbaceous creeping groundcover, commonly found growing as a weed rather than a garden plant. It has a sprawling or weakly climbing habit, and tends to grow into dense mats that smother neighbouring vegetation.

Leaves are green, sparsely hairy, opposite, smooth-edged, and egg-shaped to broadly lanceolate in shape (8 cm long, 4 cm wide).

The flowers are in small, one-sided racemes at the stem tips, with the flowers at the bottom of the raceme opening first. The individual flowers are tubular, white, up to 1 inch (2.5 cm) long, and have 5 rounded lobes, purple, vein-ridged markings on the lower lip, and 4 stamens. This species is free-flowering.

Explosively dehiscent fruits known as capsules are initially green, but becomes brown and dry after dehiscence (3.6 cm long). The fruit resembles an upside down cello and contains 4 whitish to brownish black, circular seeds which are flattened and beaked (5 mm long, 1 mm thick). Fruits contain 3 mm-long hooks which help to propel the seeds further away from the plant during explosive dehiscence.