Swainsona microcalyx, commonly known as wild violet,[1] is a species of flowering plant in the family Fabaceae and is endemic to southern mainland Australia. It is a prostrate or low-growing perennial herb, with imparipinnate leaves with 5 to 9 broadly egg-shaped to wedge-shaped leaflets and racemes of 5 to 15 purple flowers.
Swainsona microcalyx is a perennial herb, low-lying at first, then with ascending stems up to long and hairy. The leaves are imparipinnate, mostly long with 5 to 9 broadly egg-shaped leaflets with the narrower end towards the base, or wedge-shaped, the lower leaflets mostly long and wide with stipules long at the base of the petioles. The flowers are purple, arranged in racemes of 5 to 15, on a peduncle wide, each flower long on a pedicel long. The sepals are joined at the base to form a tube long, with teeth shorter than the tube. The standard petal is long and wide, the wings long and the keel long and broad. The fruit is a narrowly egg-shaped to elliptic pod about long and wide with the remains of the style about long.[2]
Swainsona microcalyx was first formally described in 1924 by John McConnell Black in the Flora of South Australia.[3] The specific epithet (microcalyx) means "a cup" referring to the shape of the sepal tube.[4]
This species of pea is mostly found north of the Eyre Peninsula in South Australia, with an outlier in inland Western Australia.