Known also as Porterweed, White Snakeweed is native to Mexico, Central America, the Caribbean and South America to Peru and Argentina. It is widely naturalised in North Queensland and north-western parts of the Northern Territory and occasionally naturalised in south-eastern Queensland where it is of particular concern, being one of the new and emerging invasive plant pests. White Snakeweed is an annual or perennial herb to 2 m tall, becoming somewhat woody towards the base. The leaf margins are serrate to crenate-serrate meaning like saw-teeth but somewhat rounded. Flowers are white, sometimes blue.
Photo: Craig W.
Leaves. Photo: Craig W.
Flowers on Flower Spike. Photo: Craig W.
Flowers on flower spike. Photo: Craig W.
Snake-like flower spike. Photo: Craig W.
Flowers Close-up. Photo: Craig W.
Flowers on flower spike. Photo: Robert Whyte