Calytrix asperula, commonly known as brush starflower, is a species of flowering plant in the myrtle family Myrtaceae and is endemic to the south of Western Australia. It is a mostly glabrous shrub with linear to narrowly elliptic leaves and cream-coloured to yellow flowers with 40 to 60 yellow stamens in several rows.
Calytrix asperula is a mostly glabrous shrub that typically grows to a height of . Its leaves are linear to narrowly elliptic, long and wide on a petiole long. There are stipules up to long at the base of the petioles. Each flower is on a peduncle long with narrowly elliptic to spoon shaped bracteoles long. The floral tube has 5 to 10 ribs and is fused to the style. The sepals are broadly elliptic to broadly egg-shaped with the narrower end towards the base, long and wide with an awn up to long. The petals are cream-coloured to yellow, long and wide and there are 40 to 60 stamens in several rows. Flowering mainly occurs from November to January.[1]
This species was first formally described in 1844 by Johannes Conrad Schauer who gave it the name Calyothrix asperula in Lehmann's Plantae Preissianae.[2] [3] In 1867, George Bentham transferred the species to Calytrix as C. asperula in his Flora Australiensis.[4] The specific epithet (asperula) means 'somewhat rough', referring to the leaves and bracteoles.[5]
Brush starflower grows in heathy scrub on sand and on flats and granite outcrops and is found between the Denmark River, Bremer Bay and the Narembeen district in the Avon Wheatbelt, Esperance Plains, Jarrah Forest and Warren bioregions of southern Western Australia.