Bossiaea is a genus of approximately 78 species of shrubs in the pea family Fabaceae, entirely endemic to Australia. It belongs to the order Fabales and is classified within the large subfamily Faboideae (papilionoid legumes). The genus is widespread across all Australian states and mainland territories, with seven species recorded in Tasmania and one, Bossiaea bossiaeoides, reaching the Northern Territory.
A distinctive characteristic of many Bossiaea species is the modification of stems and branches into flattened, leaf-like structures called cladodes. The leaves are simple and often greatly reduced — sometimes to little more than small scales — with short stipules at the base. Flowers are typically borne singly in the axils of leaves or cladodes. The calyx has five lobes, with the upper two distinctly larger and fused higher up than the lower three. Petals are predominantly orange to yellow, frequently with darker reddish or brownish markings; the standard petal is roughly twice the length of the sepals. The stamens are fused into a sheath that is open along the upper side. The fruit is a flattened pod containing seeds that bear an aril.
The genus was formally established in 1800 by the French botanist Étienne Pierre Ventenat, who described it in his work Description des Plantes Nouvelles et peu connues, cultivées dans le Jardin de J.M. Cels. The first species he described was Bossiaea heterophylla. The genus name honours Joseph Hugues Boissieu La Martinière, a botanist who participated in the La Pérouse expedition to Australia in the late eighteenth century.
GBIF recognises 59 accepted species in the genus. The Australian Plant Census accepts approximately 78 species as at July 2021, making Bossiaea one of the more species-rich genera of Australian papilionoid legumes.
Etymology
The genus name Bossiaea honours Joseph Hugues Boissieu La Martinière, a French botanist who sailed on the La Pérouse expedition to Australia in the late eighteenth century. It was coined by Étienne Pierre Ventenat when he formally described the genus in 1800.
Distribution
Bossiaea occurs throughout Australia, with species present in every state and mainland territory. Distribution is broadest in temperate and semi-arid regions; seven species are recorded in Tasmania and a single species, Bossiaea bossiaeoides, extends into the Northern Territory.
Taxonomy Notes
Bossiaea was first described by Étienne Pierre Ventenat in 1800, with Bossiaea heterophylla as the type species. It belongs to the family Fabaceae, order Fabales. GBIF lists 59 accepted species; the Australian Plant Census recognises approximately 78. The species list was last reviewed by the Australian Plant Census as at July 2021.
