The specimen, now housed in the Sherardian Herbarium,
Oxford, was for many years included in the genus Clianthus and known as
Clianthus formosus. It has since been reclassified and placed in the genus
Swainsona (after Isaac Swainson, a scientist
and plant cultivator). Formosa is the Latin formosus, for beautiful, hence the
species Swainsona formosa.
The plant is more commonly known as “Sturt’s Desert Pea” after explorer Captain Charles
Sturt, who noted the occurrence of Swainsona formosa in 1844 while exploring
between Adelaide and Central Australia. Sturt’s journal “Narrative of an
Expedition into Central Australia” makes several references to the beauty of the
desert pea in flower and the harsh nature of its habitat.
Sturt’s Desert Pea occurs
in all mainland states except Victoria and has also been seen growing in the
southern most part of the Northern Territory. It is found growing in red-brown
sandy or loamy soils on open plains, mulga shrubland and the desert regions of
Central Australia. It is found mainly in areas where there is no grazing of
livestock as the plant is eaten by cattle.
The plant can be seen growing as cultivated plantings in
Alice Springs, Alice Springs Desert Park, and Olive Pink Botanic Garden. Many
botanic gardens may also have cultivated plants on display of the Sturt’s Desert
In its natural habitat, Sturt’s Desert Pea is a perennial plant with an almost
silky grey-green pinnate foliage which grows prostrate spreading across the
ground, that has erect flower clusters. There are two recognised forms - the
inland form with a black boss, and the northern form, with a pale red boss.
Other naturally occurring hybridisation within the species have given rise to
plants with a pure white, pale pink, apricot and bicolours flower, with or
without the black boss.
Close examination shows that the leaves and stems are covered with downy hairs.
The leaves pinnate with about 13-15 hairy leaflets, that decrease in size
towards the apex.
flowers are usually arranged in a clusters of three to eight on a thick,
short, erect stalks. The flower itself are about 9 cm from tip to tip and is
usually a blood red or scarlet. A variation to the colour range from white to
deep pink. The standard petal is pointed upwards and has a shiny black,
sometimes red or pale dome (“boss”) at the base. The keel is the same length and points
downwards. There are two small “wings” petals below the boss pointing in the
same direction as the keel.
ellipsoid pods swell and are about 10-12 mm in length.
Sturt’s Desert Pea was adopted as the floral emblem of South
Australia on 23rd November, 1961, using the name Clianthus formosus.
Aboriginal Dreamtime: There are a number of stories
about the Sturt's Desert Pea from Aboriginal Dreamtime, the saddest being about
two young people from different tribes, who were in love. The flowers are known
to the Aboriginal people as 'Flowers of Blood'.
More images in our 'Snapshots of Australia: Sturt's Desert Pea'.