Dillwynia ramosissima

A low-lying to erect shrub that typically grows to 1.5 m (often smaller) with glabrous and often spiny stems.

It grows naturally in New South Wales, south from around Merriwa, through Kandos and Lithgow, as well as the northern Blue Mountains, with some records in Sydney, then with a disjunction to the Lake Burragorang area and Southern Highlands as well as Dapto. It then grows in high concentrations at Nowra, Jervis Bay and Morton National Park, with scattered records along the rest of the South Coast and Tablelands. It grows in Victoria, north of Traralgon, as well as west of Melbourne, to around Ballarat and Bendigo.

It grows in heath as well as dry sclerophyll woodlands and forest, on sandstone and 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, leaves are linear to narrow oblong or spatula-shaped, to 10 mm long and about 0.5 mm wide, on a petiole about 1 mm long, slightly twisted, smooth or with minute tubercules.

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, the flowers are arranged singly, at the terminals or in leaf axils near the ends of branchlets, yellow in colour with the standard to 10 mm long and bearing red markings. The keel is also red. Flowering primarily in late-winter and spring.

The fruit of all peas is a pod. In this species, they are approximately 7 mm long with smooth seeds.