Cyanothamnus penicillatus is a plant in the citrus family, Rutaceae and is endemic to the south-west of Western Australia. It is a low, spreading shrub with pinnate leaves and white flowers with four petals and eight stamens.
Cyanothamnus penicillatus is a spreading shrub that grows to a height of 30sigfig=1NaNsigfig=1. The leaves are sessile and pinnate with three or five leaflets, each leaflet linear to narrow wedge-shaped and NaNsigfig=1NaNsigfig=1 long. The flowers are borne singly in leaf axils on a pedicel NaNsigfig=1NaNsigfig=1 long. The four sepals are egg-shaped, NaNsigfig=2NaNsigfig=2 long and the four petals are white and NaNsigfig=2NaNsigfig=2 long. The eight stamens are slightly hairy and there is a very short point on the end of the anthers. Flowering occurs mainly from October to November.[1]
This species was first formally described in 1863 by George Bentham who gave it the name Boronia penicillata in Flora Australiensis from a specimen collected by James Drummond.[2] [3] In a 2013 paper in the journal Taxon, Marco Duretto and others changed the name to Cyanothamnus anemonifolus on the basis of cladistic analysis.[4] The specific epithet (penicillatus) is derived from the Latin word penicillum meaning "little tail", "painter's brush" or "tuft".[5]
This boronia grows in sand and has a disjunct distribution between Toodyay and the Fitzgerald River.
Cyanothamnus penicillatus is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.