Scientific name: Asclepias curassavica L.

Common name: Red head cotton bush

Family: Asclepiadaceae

Origin:

Native of tropical America.

Habit:

Erect perennial herb which may develop a woody base as it matures. Grows to about 1 m tall.

Habitat:

Common weed of disturbed sites such as roadsides, creek banks and neglected pastures.

General description:

Stems and leaves:

Stems are slender and erect and exude a milky sap (latex) if damaged. Leaves are oppositely arranged, with stalks (petioles) 0.5-2 cm long. The shape of the blade varies from narrowly elliptical to narrowly oblong (5.5-14 x 0.7-2.7 cm in size) with a pointed tip and gradually narrowing base. The underside of the leaf is a paler green than the top of the leaf (ie. leaves are discolorous). Both surfaces have scattered hairs.

Flowers and fruit:

Flowers are radially symmetrical with five brick red petals that are fused at the base (8 mm long), and a yellowish-orange central crown (4-4.5 mm across). They are borne in clusters on a stalk 3-5.5 cm long. Fruit are narrowly egg-shaped (ovoid) and tapering at both ends (6-8 cm long). They can be held on erect or ascending stalks and split lengthwise, releasing many dark brown seeds with cotton-like tufts of hairs.

Distinguishing characteristics:

Small perennial shrub with erect branches, oppositely arranged and narrow leaves, and a milky white sap. Flowers are star-like, with five brick-red petals that are fused at the base and curl backwards as the flower ages, and an orange crown-like structure at their centre. Seeds have long cottony hairs for dispersal.

Noxious status:

Not noxious.

Sources:

Kleinschmidt, H.E., Holland, A. and Simpson, P. (1996). Suburban Weeds. 3rd Edition. Department of Primary Industries, Brisbane.

Stanley, T.E. and Ross, E.M. (1983-1989). Flora of South-eastern Queensland. Volume 2. Department of Primary Industries, Brisbane.