Amaranthus viridis (AMARANTHACEAE) Green Amaranth

Weeds to Whack

An annual herb with an erect or semi-erect habit, growing to 1 m in height, native to tropical America. A common weed in gardens, roadsides, parks, pastures, cultivation and other disturbed sites. Stems can be hairless (glabrous) or sparsely hairy. Leaves are alternately arranged, entire, with petioles 7-70 mm long. The leaf blades are egg-shaped (ovate) to almost triangular in shape, tips vary, being blunt, pointed or rounded with a notch.

Photo: Robert Whyte


Flowers are small with three ‘petals’ (perianth segments) about 1.5 mm in length on branched inflorescences (5-10 cm long) and also in axillary clusters (which emerge from the forks of the upper leaves). These inflorescences can be greenish or have a pinkish or reddish-brown colour. Flowering occurs throughout the year. The fruit are 1.5-2 mm long and have a wrinkled surface. Seeds are round, black-brown in colour and with a warty texture (1-1.5 mm in size).

Photo: Robert Whyte