Variable shrub to 2 m tall. Stems branched, variously hairy. Leaves alternate, linear to narrow-elliptic, to 1.5 cm long, to 1.7 mm wide, margins entire, toothed or lobed on young plants, green and glabrous to somewhat hairy above, white- to grey-hairy below, sessile or nearly so. Capitula axillary or terminal, solitary, to 2.5 cm across, with or without stalks; spring and summer. Ray florets mauve, blue or white. Disk florets yellow or mauve. Achenes cylindrical, about 2 mm long, hairy or glandular. Pappus bristles white.
SE Australia.
An extremely variable species with several varieties recognised.
Also with smallish sessile leaves is O. microphylla (Vent.) Maiden & Betche from eastern Australia, which has light green spoon-shaped leaves, solitary capitula to 1.7 cm across that are terminal on short branchlets, and white ray florets.
Source: (2002). Dahlia. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.
Updated by: Niels Klazenga, February 2018