The Sturt’s Desert pea (Swainsona formosa) is a well-known Australian native flower that is the state floral emblem for South Australia. It belongs to the Fabaceae family. It gets its common name from the explorer Charles Sturt, who saw vast drifts of them when he was exploring the central regions of South Australia.

It is famous for its distinctive bright-colored, pea-shaped flowers, each with a bulbous black center, or "boss". The flowers grow in clusters of around half a dozen on thick vertical stalks, which are striking against the grey-green leaves. Although most of them are scarlet, there is a natural pure white form, as well as hybridised varieties which can have flowers ranging from blood-red, to pink and even pale cream, with variously coloured central bosses. Some species are recorded to be tricolored. Its flowering period occurs over a range from July to March, depending on the timing of the onset of rain to a large extent.

It spreads out as a prostrate annual or short-lived perennial with a permanent rootstock. It has pinnate, grey-green leaves which are arranged spirally on the main axis of the plant, and in two opposite rows on lateral stems. The leaves and stems are covered with downy hairs. The fruit is a legume, which splits at maturity releasing several flat kidney-shaped seeds.

It is well adapted to life as a desert plant. The small seeds have a long viability and can germinate after many years. Seeds have a hard seed coat, which protects them from harsh arid environments until the next rainfall but inhibits germination in normal domestic environments. To break the dormancy, place seeds in water that has just boiled and leave them overnight. In the morning the seeds will have swelled to the size of match heads.