Scoparia dulcis L.

Plantaginaceae

Linnaeus, C. von (1753) Species Plantarum 2: 116. Type: Habitat in Jamaica, Curassao.

Scoparia; Scoparia Weed

Usually flowers and fruits as a herb but occasionally grows into a shrub about 1 m tall.

Leaves usually in whorls of three, leaf blades variable, about 1-3 x 0.3-1.5 cm, glandular, particularly on the lower surface.

Calyx lobes about 1 mm long, corolla lobes about 2 mm long. A ring of long hair-like structures present in the same whorl as the stamens. Ovary surrounded by a ring of hairs and seated on a glandular disk. Ovules numerous, attached to a fleshy central placenta.

Seeds small, less than 0.5 mm long, about twice as long as wide.

Cotyledons about 2 x 1.5 mm. Hypocotyl terete. First pair of leaves with toothed margins, stem 4-angled. At the tenth leaf stage: oil dots just visible with a lens, stem 4-angled or shortly 4-winged. Numerous small hair-like glands present on the stems between the petioles of each leaf pair. Seed germination time 27 to 43 days.

An introduced species originally from tropical America, now naturalised in WA, NT, CYP, NEQ, CEQ and southwards as far as north-eastern New South Wales. Altitudinal range in northern Australia from near sea level to 1000 m. Usually grows as a weed of agricultural land but also found in disturbed areas and along roads in rain forest.

Scoparia dulcis var. typica Domin, Bibliotheca Botanica 89(4): 1151(1928), Type: Diese breitblattrige Varietat ist in Australien vielleicht nur eingeschleppt, so z. B. bei Cairns also Undraut (DOMIN Dec.1909), Goodna, C.T. White. Scoparia dulcis L. var. dulcis, Bibliotheca Botanica 89(4): 1151(1928).