Swainsona
Australian native legumes with purple pea-like flowers
Swainsona is a group of about 85 flowering plants found only in Australia. They are herbs or low shrubs with divided leaves and flowers that resemble peas, usually purple but sometimes white, pink, yellow or red.
- Found only in Australia, including all states and territories
- Flowers usually purple but also white, pink, yellow or red
- Contains swainsonine, a toxin causing 'pea struck' in livestock
- Sturt's desert pea is South Australia's state flower
- Leaves are pinnate with a terminal leaflet
What does Swainsona look like?
Swainsona plants grow close to the ground or upright, with many stems from the base. Their leaves are made of several leaflets arranged along a central stalk, ending in one final leaflet. The flowers grow in clusters on stalks rising from leaf joints. Each flower has a bell-shaped base of joined sepals and five petals, typically purple but also found in white, pink, yellow or red. The upper petal is rounded and larger than the others.
Where does Swainsona come from?
All Swainsona species are native only to Australia. The genus was named after English botanist Isaac Swainson. It belongs to the legume family and is related to certain New Zealand plants like kakabeak and scree pea. Some species contain swainsonine, a toxin that affects livestock, causing a condition known locally as 'pea struck'.
When and how Swainsona blooms
These plants grow as annuals or perennials across varied Australian habitats. They produce flowers in racemes from leaf axils. While the exact flowering time varies by species and region, they thrive in native soils without mention of specific cultivation needs beyond their natural range.
How Swainsona is used
Some Swainsona species, especially Sturt's desert pea (Swainsona formosa), are recognized as floral emblems, this one is the state flower of South Australia. Several species are known to be poisonous to grazing animals due to swainsonine, limiting their use beyond ornamental or symbolic roles.
Kinds of Swainsona
The genus includes around 85 accepted species. Notable ones include Swainsona formosa (Sturt's desert pea), Swainsona galegifolia (smooth Darling pea), and Swainsona laxa (yellow Darling pea). Species differ in leaf shape, flower colour, growth habit, and habitat, ranging from coastal to arid inland regions.
What Swainsona means
Swainsona formosa is the floral emblem of South Australia. The plants have no noted role in religious practice but are significant in Australian botany. Their toxicity to livestock is well documented, with affected animals described as 'pea struck'. They are not used in food or medicine due to this poison.
Questions people ask about Swainsona
Where does Swainsona come from?
Swainsona is endemic to Australia and grows in all its states and territories.
What do Swainsona flowers look like?
They resemble pea flowers, mostly purple but also white, pink, yellow or red, with a rounded upper petal and clustered blooms on upright stalks.
Is Swainsona poisonous?
Yes, some species contain swainsonine, a toxin that harms livestock, causing a condition called 'pea struck' in Australia.
Is any Swainsona species an emblem?
Yes, Swainsona formosa, known as Sturt's desert pea, is the state floral emblem of South Australia.
How many Swainsona species are there?
About 85 species are currently accepted, all native to Australia.
Good reading and sources
- Plants of the World OnlineRoyal Botanic Gardens, Kew, Plant database
- Where it has been recordedGBIF, Plant database
- Sightings and photos by naturalistsiNaturalist, Plant database
The facts on this page come from the Wikipedia article "Swainsona", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). Phool rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes. It is not medical or foraging advice: many flowers are poisonous, and traditional uses are reported, not recommended. If something is wrong, tell us. Last refreshed 2026-10-03.
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