Hybanthus monopetalus, the Slender Violet-bush is a common plant in the violet family

Violaceae

Violaceae are a family of flowering plants consisting of about 800 species in 21 genera. It takes its name from the genus Viola, the violets and pansies.Older classifications such as the Cronquist system placed Violaceae in an order named after it, the Violales...

.
It is found in eastern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 in dry eucalyptus

Eucalyptus

Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...

 woodland, often in sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 or granite

Granite

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

 derived soils, where it is seen growing in relatively shady moist sites, surrounded by dry open country. It may reach 30 cm in height. Flowers form on short raceme

Raceme

A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...

s at the end of branches. The specific epithet monopetalus translates to "one petal".