Canad. J. Bot. 40: 1245 (1962) APNI
Perennial herb, mostly 20-40 cm high, rhizomatous; stems several, often decumbent at base then erect, sparsely branched, glabrescent to pubescent. Leaves subsessile, opposite below, alternate above, ovate to elliptic, mostly 10-30 mm long and 3-10 mm wide, surfaces appressed-pubescent, concolorous, grey-green, apex sub-acute to obtuse, base narrowed, margins entire. Inflorescences erect leafy racemes 3-12 cm long. Capitula solitary in leaf-axils, 4-6(-8) mm diam., nodding; peduncles 2-15 mm long; involucral bracts ovate, c. 3 mm long, connate for more than half their length, obtuse, pubescent. Florets c. as long as involucre, greenish-yellow; outer florets 1-10; inner florets 9-25(-50). Cypselas obovoid, 1.5-3 mm long, flattened on inner face, scurfy, brown to dark grey. Flowers mainly summer.
Also naturalised SA. Native to North America. In Victoria known only by a few collections from the Kerang, Quambatook and Swan Hill areas and an old specimen from Newstead. Collected from pasture and fallow land.
Declared a noxious weed in Victoria, and by its extensively rhizomatous habit and its tendency to chemically inhibit germination of other species, a potential threat to crops and pasture, particularly on saline and alkaline soils