Thomasia petalocalyx, commonly known as paper flower, is a species of flowering plant in the family Malvaceae and is endemic to southern Australia. It is a shrub with wrinkled, oblong to egg-shaped leaves and cup-shaped mauve flowers.
Thomasia petalocalyx is a shrub that typically grows to high, wide and has its new growth covered in star-shaped hairs. The leaves are oblong to egg-shaped, long and wide on a petiole long with hairy brown, wing-like stipules long at the base of the petioles. The leaves are covered with star-shaped hairs, and the edges are wrinkled, turned down and finely toothed. The flowers are arranged singly or in racemes of up to 5 on a red peduncle long near the ends of the branches. Each flower is on a pedicel long, with 3 bracteoles long at the base. The sepals are mauve and form a cup-shaped flower wide, the petals deep red and tiny.[1] [2] [3]
Thomasia petalocalyx was first formally described in 1855 by Ferdinand von Mueller and the description was published in his book Definitions of rare or hitherto undescribed Australian plants.[4] [5] The specific epithet (petalocalyx) refers to the petal-like sepals.
Paper flower grows in forest, woodland, coastal heath and on granite outcrops in the Esperance Plains, Jarrah Forest and Mallee bioregions of southern Western Australia, in the south-east of South Australia, including on Kangaroo Island, and in scattered locations in the west and south-west of Victoria, with an isolated population on Wilsons Promontory, where it is common.