Parthenium Weed

Parthenium hysterophorus
Family: Asteraceae

Growth Habit: Reaching a possible height of two metres, this herb with a deep tap root and erect stem can develop a woody stem and many branches on maturity. Parthenium weed has pale green leaves with soft fine hairs.

Type of Plant: An annual herb.

Flowers: The flowers are small, creamy white. Each contain 4 to 5 black seeds.

Fruit/Seed: Seeds are wedge shaped, 2mm long with 2 thin white scales.

Dispersal: Parthenium weed seeds are dispersed via water, vehicles, machinery, stock, animals (both native and feral), in feed and seeds.

Distribution: Parthenium is found in Central Queensland with isolated infestations west to Longreach and in Northern and Southern Queensland. Also there are infestations in northern and central parts of New South Wales. However it is capable of growing in most states.

Status: Parthenium is a Weed of National Significance.

Weed Impact:

  • Reduces reliability of improved pasture development
  • Reduces pasture production development
  • Can cause allergic reactions including dermatitis and hay fever

Information referenced from “Queensland Government, Department of Natural Resources Pest Fact No PP2.”