Dillwynia glaberrima

A spreading or erect shrub which grows to 2 metres high and 1 metre wide, usually with hairless stems.

It has a mainly coastal occurrence in NSW, growing close to the coast and inland, in disjunct patches, as far west as Wollemi National Park towards the Hunter Valley (north-west of Sydney / west of Newcastle). It extends along the coast to just south of Fraser Island in Queensland, as well as along most of the Victorian coast and inland central areas, to the east of South Australia, as well as over most of Tasmania.

It is found in dry sclerophyll woodland and open forest, heathy forest and heathland, usually on sandy soils or rocky areas.

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 linear, to 20 mm long, to 1 mm wide, smooth and generally hairless, with a recurved acuminate tip.

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 bright yellow, about 10 mm in diameter, and have an orange throat with red markings on the standard. These appear in dense clusters at the end of the wiry branchlets from August to December.

The fruit of all peas is a pod. In this species, they are to 6 mm long, with sparse hairs.