A prostrate to spreading shrub to 1 metre tall, to less than 1 metre wide, with stems with small hairs.
It occurs naturally in NSW and Qld; growing on the coast of NSW as far south as the Clyde River (Batemans Bay), extending north through the central coast subdivision, to as far west as Lithgow and Kandos, then extending north mainly along the coast to south-east of Gympie in Queensland. There are also some disjunct records inland from Bundaberg.
It grows in dry forest and woodland, sometimes on coastal headlands, on shallow sandstone soils.
Dillwynia is a member of the “pea” family. This generally means that leaves are alternate with stipules at the base of the petioles. Dillwynia have simple and alternate leaves, with stipules present and minute, or absent.
Leaves can be flat, terete or triangular in cross-section and often twisted.
In this species, leaves are to 5 mm long, and about 1 mm wide, spirally twisted, with the tips curved and pointed, smooth to warty with hairs coming out of the tubercules (warts), or hairless, mid to dark green in colour.
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 Dillwynia, flowers are yellow, or red and yellow (or orange/yellow) and are usually arranged singly or in small groups in leaf axils or on the ends of branchlets. The upper two of five sepal lobes are joined in a single “lip”. The standard petal is typically wider than high (a useful identification feature), and the keel is the same length as the wings. There are very small leafy bracts present on the common peduncle (which can fall early or be persistent) and bracteoles on flower pedicels (below the calyx).
In this species, flowers are borne singularly or up to clusters of 6 in terminal umbels, orange-yellow to yellow in colour, with the standard to 6 mm long and with striking red markings. The keel may also be red.
The fruit of all peas is a pod. In this species, they are approximately 5 mm long with a reticulate pattern on the seeds.
Not a lot of knowledge is available regarding the successful cultivation of this species. It may not have been trialled to a large extent. It grows naturally on shallow sandy soils, so it may need this to thrive. May be short-lived.
In a garden situation, Dillwynias are not overly common in cultivation and are only occasionally grown by enthusiasts. They are generally suited to well drained soils in a sunny or semi-shaded position and most will tolerate heavy pruning.
Propagation from seed is relatively easy following pre-treatment to break the physical dormancy provided by the impervious seed coat. Pre-treatment can be carried out by abrasion or soak in near-boiling water for about 30 seconds, before cooling rapidly under flowing cold water. Alternatively soak in cold water for several hours.
Dry to prevent rotting before sowing. Germination occurs in 3-4 weeks.
Cuttings strike reasonably well using firm, current season’s growth.
This species was formerly known as D. parviflora subsp. trichopoda and Dillwynia sp. Trichopoda (informally).
Dillwynia is a genus of about 40 species of flowering plants endemic to Australia and occurring in all Australian states and the Australian Capital Territory (except the Northern Territory). They are generally small to medium-sized shrubs. They are often known by the name of ‘Eggs and Bacon’ or ‘Parrot-peas’ because of their bright yellow and reddish tints of the flowers.
Dillwynia plants (as well as Acacia) are often colonising species which germinate quickly after fires to stabilize the soil and to provide nitrogen (all are legumes able to “fix” nitrogen from the atmosphere in nodules on their roots). NSW currently has about 22 taxa.
The following link is a list of Dillwynia species accepted by the Australian Plant Census and Plants of the World Online as at May 2021:
Dillwynia spp. will mostly regenerate from seed after fire.
Dillwynia – honours Lewis Weston Dillwyn (1778-1855) who was a British porcelain manufacturer, naturalist and Whig Member of Parliament (MP). He was also renowned for his published works on botany and conchology.
trichopoda – from Greek trichotos (τριχωτός) meaning “hairy” and podia (πόδια) meaning “feet”, referring to the hairy calyx lobes of the species.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Dillwynia trichopoda profile page
Plants of South Eastern New South Wales – Dillwynia sp. Trichopoda profile page.