Euphorbia hirta L.

Linnaeus, C. (1753) Species Plantarum 1: 454. Type: Habitat in India.

Asthma weed

Stems clothed in hairs. Stems produce a milky exudate when cut or broken.

Leaf blades about 25-50 x 11-26 mm, petioles about 2-4 mm long. Both the upper and lower surfaces of the leaf blade and the petioles clothed in hairs. Lateral veins 2-4 on each side of the midrib. Stipules linear, about 1.5-2 mm long, hairy.

Flowers in clusters which are arranged in heads. Clusters consist of one female flower together with 1-7 male flowers. Each cluster surrounded by an involucre of 4 glands. Male flowers: Male flowers consist of a single anther and bract which is fimbriate at the apex. Female flowers: Ovary green, about 1.1 mm diam., clothed in hairs. Styles 3 or absent. Stigmas 6.

Fruits 3-lobed, about 1 x 1.1-1.2 mm, clothed in hairs.Seeds about 0.7-0.8 mm diam.

Embryo about 0.5-0.6 mm long, the cotyledons much wider than the radicle.

An introduced species in WA, NT, CYP, NEQ, CEQ and south into New South Wales. Altitudinal range from near sea level to 900 m. Grows in margins of rainforest, Eucalypt forest, notophyll vine forest, various types of woodland and in wooded grassland. From the tropical and subtropical regions in both hemispheres.

Common weed of disturbed areas.

An infusion is used as a cure for asthma and bronchitis (Webb 1948).