Scientific name: Asclepias curassavica L.
Common name: Red head cotton bush
Native of tropical America.
Erect perennial herb which may develop a woody base as it matures. Grows to about 1 m tall.
Common weed of disturbed sites such as roadsides, creek banks and neglected pastures.
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.
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.
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.