An erect to open shrub, to 2 metres tall with stiff, spreading hairs on the stems.
In NSW, it grows predominantly on the tablelands, extending into the western slopes and slightly into the coastal areas. It extends as far north as west of Rockhampton in Queensland, coming south through the inland, through Toowoomba and Warwick and down to the Tamworth-Armidale area of NSW and further east.
From around Nundle, plants are only found to the west, to as far as Coonabarabran, then flowing south-eastwards to Sydney, as well as Cowra-Orange and Bathurst, with occurrences then mostly on the southern tablelands to the Victorian border.
The species also grows extensively in mostly the eastern half of Victoria.
Grows in dry sclerophyll forest and woodland, usually on acidic sandy 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 the leaves are moderately clustered on the stems, spirally-twisted, linear to narrow oblong, to about 10 mm long and only 0.5 mm, bright to mid green in colour. Leaves usually have stiff short hairs and may have tubercules (glands).
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, inflorescences are usually in terminal heads (capitate), consisting of up to 8 flowers, yellow in colour but with other hues as well. The standard is up to 12 mm long, with red to purple markings. The keel can also be red to purple-red; flowering mainly from September to December.
The fruit of all peas is a pod. In this species, they are oval, approximately 7 mm long and with hairs.
Limited information is available regarding the cultivation of this species. It may be more widely cultivated in the future. It has a large natural range and is common, which might mean it is adaptable to some garden environments. It typically grows on sandy soils and so may need such conditions in a garden to thrive.
Dillwynias are not overly common in cultivation and only occasionally grown by enthusiasts. This species is suited to well drained soils in shady and dappled shade positions. Mass plant for best effect. Pruning after flowering is beneficial.
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.
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. NSW currently has about 22 taxa.
Dillwynia plants (as well as Acacia) are often colonising species which germinate quickly after fires to stabilise the soil and to provide nitrogen (all are legumes able to “fix” nitrogen from the atmosphere in nodules on their roots).
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.
phylicoides – Latin meaning “Phylica-like”. Phylica is a genus of plants in the family Rhamnaceae, occurring mostly in South Africa.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Dillwynia phylicoides profile page
Wikipedia – Dillwynia phylicoides profile page