Alternanthera pungens

About

Alternanthera pungens is a creeping, prostrate perennial pioneer plant of the family Amaranthaceae, spreading by seed and vegetatively, with roots often developing at the nodes of spreading stems. A plant of roadsides, path verges and waste places (ruderal), it is thought to have come from Central and South America, and to have become widely established in Australia and Southern Africa. Other species of this genus, e.g. Alternanthera sessilis (L.) R.Br. ex DC., have long been recorded from Tropical Africa, and would be difficult to prove as invaders.

Summary from Wikipedia