Explorer Charles Sturt's name given to hardy beauty of desert pea: South Australia's floral emblem from 1961
Captain Charles Sturt noted Swainsona formosa in 1844 while exploring between Adelaide and central Australia.
Sturt's desert pea, Swainsona formosa, was adopted as South Australia’s floral emblem in 1961. A member of the fabaceae pea family, it is confined to all Australian mainland states except Victoria.
British navigator William Damper collected a specimen in 1699 on Rosemary Island off the Western Australian coast. This specimen was later housed in the Sherardian Herbarium at Oxford in England.
Captain Charles Sturt noted Swainsona formosa in 1844 while exploring between Adelaide and central Australia. Sturt's journal, Narrative of an Expedition into Central Australia, referred several times to the beauty of the desert pea in harsh habitat. The genus Swainsona honours Isaac Swainson who had a private botanic garden at Twickenham near London in about 1789. Formosa is Latin for “beautiful”. Original author of the species was Scottish botanist George Don (1798-1856).
In its natural habitat, Sturt's desert pea is a perennial plant with silky grey-green pinnate foliage arising from prostrate stems. The leaves and stems are covered with downy hairs. The flowers are about 9 cm long and in clusters of six to eight on short thick erect stalks. The petals are usually blood red or scarlet with a glossy black swelling or “boss” at the base of the uppermost petal: the standard. Other colours range from white to deep pink, either with or without a black boss, and rarely bicoloured where the standard is scarlet and the other petals, the wings and keel, are white tipped and edged with scarlet.
The fruit is a legume about 5 cm long that splits at maturity releasing several flat kidney-shaped seeds. Sturt's desert pea occurs in arid woodlands and on open plains, often as an ephemeral after heavy rain. It can withstand the marked extremes of temperature of inland deserts, and light frosts are tolerated by established plants.
Sturt's desert pea is protected in South Australia. The flowers and plants must not be collected on private land without the written consent of the owner. Collection on crown land is illegal without a permit.