Shrub, 0.5–1.5 m high; young stems indistinctly 4-ridged, older stems more or less terete. Leaves ovate to elliptic,12–25 mm long, 5–14 mm wide, bases cuneate, sometimes tapered to a short petiole-like base, lower surface slightly paler than upper, tertiary nerves finely reticulate, indistinct. Flowers, solitary, terminal or on short branches from upper leaf axils; sepals equal, or one slightly longer, obovate to spathulate, 3–7 mm long, deciduous, not black-dotted; petals narrowly obovate, 12–18 mm long, golden-yellow, not black-dotted; stamens numerous, united at base into 5 bundles, slightly shorter than petals; styles 3, 2–5 times longer than ovary. Fruit ellipsoid to subcylindrical, 8–13 mm long, initially somewhat fleshy, ultimately dry, dehiscent (fruit not seen in Victoria). Flowers Dec. (1 record).
Sometimes cultivated, and sometimes the parent species of other cultivars. Several subspecies are known and it is likely that the Victorian plants are H. hircinum subsp. cambessedesii (Coss ex Nyman) Sauvage, the smallest-leaved member of the species, but the possibility exists that the Victoria collection is of hybrid, cultivated origin.
Some subspecies of H. hircinum are described as ‘smelling of goat’ from the presence of caproic acid. The Red Cliffs collection is not conspicuously odorous.
