Beside the road between Roxby Downs and Andamooka was a sizable field of Sturt's Desert Pea (Swainsona Formosa), blooming sparsely among the native grass and other low growing plants.
The Sturt's Desert Pea is such a captivating icon, the state flower of South Australia and a brilliant red, standing out among the drab, dry grass.
Sturt's Desert Pea really is such an attractive flower, seen in prolific numbers in the sand dune country of the arid region. Usually brilliant red, it stands out against the red sand, desert stones and other plants, so much so that Lesley bought a packet of seed to grow at home.
If we can successfully establish them, they'll look quite something along side our collection of outback rocks, petunias and snap dragons.
Sturt's Desert Pea is a member of Fabaceae, subfamily Faboideae. It has pinnate, grey-green leaves which are arranged spirally on the main axis of the plant, and in two opposite rows (distichous) on lateral stems. Its flowers are so different from its relatives that it is almost unrecognisable as a member of the pea family. The flowers are about 9 centimetres in length and grow in clusters of around half a dozen on thick vertical stalks (peduncles), which spring up every 10-15 centimetres along the prostrate stems, which may be up to 2 metres in length. The sexual organs, enclosed by the keel, comprise 10 stamens, of which 9 are joined and 1 is free, and an ovary topped by a style upon which is located the stigma which receives pollen during fertilisation.
The plant flowers from spring to summer, particularly after rain. There is a natural pure white form, as well as hybridised varieties which can have flowers ranging from blood scarlet, to pink and even pale cream, with variously coloured central bosses. Several tricolour variants have been recorded, including the cultivars marginata (white keel with red margin, red flag and purple-black boss), tricolour (white keel, red flag, pink boss), and elegans (white flag and keel, both with red margins). Flowers are bird-pollinated in the wild.
The fruit is a legume, about 5 centimetres long, and each yields 50 or more flat, kidney-shaped seeds at maturity
Most forms of the plant are low-growing or prostrate, however in the Pilbara region of north-western Australia varieties growing as tall as 2 metres have been observed.