An erect shrub that typically grows to a height of 2 metres.
It is known from two disjunct areas in eastern New South Wales on the central coast and then the southern tablelands botanical subdivision; with the former from the lower Blue Mountains in the Warragamba area from Lake Burragorang west / south-west to Taralga; then with the latter having records around Goulburn and Crookwell with an abundant occurrence between Tarago and Nerriga (near a locality known as Windellama).
It is a listed threatened species.
It is found in dry sclerophyll woodland on stony slopes or ridges, sometimes on sandstone or loam-soil.
Young stems are hairy. The bark of older plants is distinctly flaky.
Bossiaea spp. have two ‘versions’ of foliage. Some species have simple leaves (sometimes described as uni-foliolate), arranged alternately or oppositely. Other species have leaves reduced with flattened or winged stems modified to cladodes, with mostly only juvenile growth having small leaves. As this is a member of the ‘pea’ family, stipules are present though usually small. In this species, true leaves are alternate, broadly elliptic to more or less round, to 5 mm long and wide, with the apex recurved; with hairy to glabrous upper surfaces and with the lower surface often with soft crinkled hairs; green to blue-green in colour; with dark brown stipules 1.0 to 1.5 mm long.
Flowers are, of course, pea-shaped (a term sometimes used is papilionate), with 5 petals in a fixed arrangement; the main back petal is called the “standard”, two lateral petals called “wings” and two fused petals at the bottom called the “keel” (in which the anthers and one carpel tend to be hidden). In this species, flowers are borne singularly in leaf axils, to 11 mm long; the standard and wings are bright yellow with red markings and the keel is dark red. Flowering occurs from August to November.
The fruit of all peas is a pod. In this species, they are to 17 mm long and somewhat elliptic.
Bossiaea species are a particular attractive garden plant of the “bacon and eggs” element of the Australian bush. However they are not often cultivated but are sometimes grown by Australian plant enthusiasts. When species such as B. heterophylla, B. walkeri and B. scolopendria are seen in the wild in full flower, it is hard not to ask “Can I grow this one?”
Reportedly, they are easy enough to grow. It may be simply a matter of acquiring seeds or tubestock from native nurseries or online. Some species are known for not setting a lot of seed and seed can also be hard to germinate in some cases. If plants or seeds can be sourced, they are generally readily cultivated in a sunny well drained position.
Not a lot if known about the cultivation of this species. It is a listed threatened species and therefore, may be hard to source from nurseries. Check with native nurseries for availability. It likely needs a well-draining soil in some sun for best results. Can likely tolerate frosts.
Propagation of Bossiaea seeds needs treatment before sowing. This is done by allowing the seeds, which have a hard seed coat, to stand in boiled water for 12 hours. The softened seeds then swell and are ready for sowing. The seeds are best sown in a mixture of three parts coarse sand and one part peat moss or similar.
Seed, however, is not often available.
Cuttings strike reasonably well from firm, current season’s growth.
Bossiaea oligosperma may be confused with Bossiaea obcordata, a common pea in eastern NSW, but B. obcordata has spiny branches and is generally a smaller plant. It might also be confused with B. neoanglica which is a smaller plant with longer and hairy pods that have more seeds.
This species was only formally described relatively recently in 1981.
Bossiaea is a genus of at least 50 species (likely more), endemic to Australia. They are found in all States and are mostly small to medium shrubs. NSW currently recognises 30 species.
This species grows in fire-prone habitats and likely regenerates from seed after fire.
Bossiaea – named after Joseph Hugues Boissieu de la Martinière (1758-1788), a physician and plant collector who participated in the expedition of Jean-Francois de La Perouse in 1785. He disappeared in the Pacific whilst a member of this expedition, when ships were lost in the Solomon Islands. The genus was named by botanist Etienne Pierre Ventenat.
oligosperma – Greek oligoi (ολίγοι) meaning “few” and –sperma (σπέρμα) meaning “seed” – capturing the condition of the pods never having more than 3 seeds.
This plant is listed as threatened with extinction in the wild, at both the State and Commonwealth level, with the category of vulnerable.
NSW Flora online (PlantNET) – Bossiaea oligosperma profile page: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Bossiaea~oligosperma
Wikipedia – Bossiaea oligosperma profile page https://en.wikipedia.org/wiki/Bossiaea_oligosperma
NSW Office of Environment and Heritage – Threatened Species Profiles – Bossiaea oligosperma profile page: https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10104