A small shrub, to 40 cm tall by 30 cm wide.
It has a very small natural occurrence in NSW, restricted to the Woronora Plateau, in a small area between Helensburgh, south of Sydney, and Mt Kiera above Wollongong.
It grows in moist and dry sclerophyll woodland, as well as wet heath, on Hawkesbury sandstone.
It is a listed threatened species in the wild.
Pultenaea is a member of the “pea” family. This generally means that leaves are alternate with stipules (leaf-like appendages) at the base of the petioles. Pultenaea spp. however, can sometimes have opposite leaves or leaves in whorls of 3. One of the key features of Pultenaea is that the stipules are fused behind the axillary bud.
In this species, the leaves are alternate, narrow and concave, to 25 mm long and 2 mm wide, with warty structures (tubercules) and unmistakably tipped with a conspicuous awn. There is a pair of stipules (leafy bracts) at the base of each leaf.
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).
Pultenaea spp. sometimes have bracts surrounding the inflorescences, and bracteoles attached to the calyx tube or just below on the pedicels (at different locations in different species). These bracteoles can also have accompanying stipules.
In this species, flowers are yellow, about 12 mm long, with the standard bearing red markings, and with a red keel. Flowers are clustered in heads at the branch tips in groups of 5 to 10, surrounded by bracts. Each flower is attached to a pair of enlarged stipules and are covered with long white hairs.
The fruit of all peas is a pod. In this species, they are oval, approximately 6 mm long and swollen.
Not a lot of knowledge is currently available regarding this species in cultivation. This is likely because it is a threatened species. It may be more commonly cultivated in the future. It grows on sandstone shelves or skeletal sandstone soils naturally, and so may need similar garden conditions to thrive.
Pultenaeas are not all that common in cultivation but can be sourced and are worth trying. Many members of this genus can be a little difficult to establish in a garden situation. They prefer soil with moderate drainage and semi shaded site. Prune after flowering to maintain compactness.
Propagation is carried out by either cuttings or seed and results are reasonably good from both methods.
Cuttings should be from newer wood with the soft tips removed.
A lot of seed is destroyed by insects, resulting in a low number of viable seeds.
Before seeds are sown, they must be treated by chipping, scarifying or hot water, which are all satisfactory methods to aid germination.
There are approximately 120 species of Pultenaea, making it the largest pea-genus. They are endemic to Australia and occurring in all States except the Northern Territory. NSW currently has about 95 taxa with some informally recognises and some that are species-complex.
This genus contains some species complexes and is under taxonomic revision.
Pultenaea spp. will generally regenerate from seed after fire.
Pultenaea – is named in honour of Dr Richard Pulteney (1730–1801) – an English botanist who published a biography of Carl von Linne (Linnaeus).
aristata – Latin meaning “bearing a bristle-tip”, referring to the leaf tips.
This species is listed as threatened with extinction at the State and Commonwealth level, with the category of vulnerable at both levels.
NSW Flora Online (PlantNET) – Pultenaea aristata profile page
NSW Office of Environment and Heritage – Threatened Species Profiles – Pultenaea aristata profile page
Wikipedia – Pultenaea aristata profile page