Swainsona is a large genus of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s native to Australasia

Australasia

Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...

. There are 85 species, all but one of which is endemic to Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

; the exception, S. novae-zelandiae, occurs only in New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

.

A member of the family Fabaceae

Fabaceae

The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...

 (legumes, it is most closely related to the New Zealand genera Montigena (scree pea), Clianthus (kakabeak), and Carmichaelia (New Zealand broom

New Zealand Broom

Carmichaelia is a genus of 24 plant species belonging to Fabaceae, the legume family. All but one species are native to New Zealand...

).

Swainsona is named after English botanist Isaac Swainson

Isaac Swainson

Isaac Swainson was the son of John Swainson , yeoman, of High House, Hawkshead, Lancashire. He was famous for his botanical garden, which was largely funded from the profits of a herbal remedy for venereal disease, and a plant genus is named after him. For his commercial activities in the latter...

.

A few species are known to produce swainsonine

Swainsonine

Swainsonine is an indolizine alkaloid. It is a potent inhibitor of Golgi alpha-mannosidase II, an immunomodulator, and a potential chemotherapy drug...

, a phytotoxin

Phytotoxin

Phytotoxin refers to a substance produced by a plant that is toxic or a substance that is toxic to the plant Many substances produced by plants are secondary metabolites and are the by-products of primary physiological processes...

 harmful to livestock

Livestock

Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

 (see Locoweed

Locoweed

Locoweed is a common name in North America for any plant that produces swainsonine, a phytotoxin harmful to livestock. Worldwide, swainsonine is produced by a small number of species, most in three genera of the flowering plant family Fabaceae: Oxytropis and Astragalus in North America, and...

). In Australia, animals intoxicated with swainsonine are said to be pea struck.

Selected species

• Swainsona acuticarinata (A.T.Lee) Joy Thomps.
• Swainsona adenophylla J.M.Black
• Swainsona affinis (A.T.Lee) Joy Thomps.
• Swainsona beasleyana F.Muell.
• Swainsona behriana
  Swainsona behriana
  Swainsona behriana, commonly known as Southern Swainson-pea, is a small perennial plant in the family Fabaceae that is native to Australia. It grows to 15 cm high, has hairy stems and pinnate leaves that are 3 to 5 cm long. Racemes of 2 to 7 purple pea flowers are produced from August to January...
  
  F.Muell. ex J.M.Black
• Swainsona brachycarpa Benth.
• Swainsona bracteata (Maiden & Betche) Joy Thomps.
• Swainsona burkei F.Muell. ex Benth.
• Swainsona burkittii F.Muell. ex Benth.
• Swainsona cadellii F.Muell. ex C.Moore & Betche
• Swainsona calcicola Joy Thomps.
• Swainsona campestris J.M.Black
• Swainsona campylantha F.Muell.
• Swainsona canescens (Benth.) F.Muell.
• Swainsona colutoides F.Muell.
• Swainsona complanata Joy Thomps.
• Swainsona concinna F.M.Bailey
• Swainsona cornuta Joy Thomps.
• Swainsona coronillifolia Salisb.
• Swainsona cyclocarpa F.Muell.
• Swainsona decurrens A.T.Lee
• Swainsona dictyocarpa J.M.Black
• Swainsona disjuncta Joy Thomps.
• Swainsona ecallosa Sprague
• Swainsona elegans A.T.Lee
• Swainsona elegantoides (A.T.Lee) Joy Thomps.
• Swainsona eremaea Joy Thomps.
• Swainsona extrajacens Joy Thomps.
• Swainsona fissimontana J.M.Black
• Swainsona flavicarinata J.M.Black
• Swainsona formosa (G. Don) Joy Thomps. - Sturt pea
• Swainsona forrestii F.Muell. ex A.T.Lee
• Swainsona fragilis F.M.Bailey
• Swainsona fraseri Benth.
• Swainsona fuscoviridis Joy Thomps.
• Swainsona galegifolia
  Swainsona galegifolia
  Swainsona galegifolia is a flowering plant in the genus Swainsona in the family Fabaceae, native to Australia. It produces swainsonine.- References :*...
  
  (Andrews) R.Br.
• Swainsona gracilis Benth.
• Swainsona greyana
  Swainsona greyana
  Swainsona greyana, commonly known as Darling Pea or Hairy Darling Pea, is a shrubby perennial in the family Fabaceae that is native to Australia. It grows to 1.5 metres high, has hairy stems and pinnate leaves that are 10 to 15 cm long. Racemes of 12 to 20 pea flowers are produced from September...
  
  Lindl.
• Swainsona halophila Joy Thomps.
• Swainsona incei W.R.Price
• Swainsona kingii F.Muell.