Thomasia macrocalyx

Thomasia macrocalyx is an erect, bushy shrub that typically grows to a height of 0.3–2.5 m (1 ft 0 in – 8 ft 2 in), its young growth densely covered with pale or brownish, star-shaped hairs. The leaves are egg-shaped with a heart-shaped base, 40–80 mm (1.6–3.1 in) long and 25–50 mm (0.98–1.97 in) wide on a petiole 15–30 mm (0.59–1.18 in) long. The edges of the leaves are toothed or lobed, both surfaces densly covered with star-shaped hairs, the upper surface becoming glabrous with age. The flowers are arranged in hairy racemes of 2 to 6, 50 mm (2.0 in) long with egg-shaped bracteoles 10 mm (0.39 in) long at the base, the flowers 20–25 mm (0.79–0.98 in) in diameter. The sepals are joined at the base and covered with both simple and star-shaped hairs. Flowering occurs from May to December.[2][3]

Thomasia macrocalyx was first formally described in 1845 by Ernst Gottlieb von Steudel in Lehmann's Plantae Preissianae from specimens collected near Preston Beach.[4][5] The specific epithet (macrocalyx) means "large calyx", referring to the sepals.[6]

This thomasia grows on sandplains, hills and breakaways, often near creeks or on slopes, mainly near the Darling Range in the Avon Wheatbelt, Esperance Plains, Geraldton Sandplains, Jarrah Forest, Mallee and Swan Coastal Plain bioregions of south-western Western Australia.[2][3]

Thomasia macrocalyx is listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.[3]