Family: Fabaceae (Caesalpinoidae)

Status:

Description:
Straggly evergreen shrubs 1 to 3m high. Leaves are compound with 3-8 pairs of leaflets. There is a raised gland between the lowest pair, or few pairs, of leaflets. Flowers are large and showy, with protruding curved stamens (the pollen-producing parts). Seed pods are cylindrical and bean-like.

Preferred habitat and impacts:
Mostly found in bush around towns and old farms. They can be spread some distance from habitation, presumably by birds, although the seeds are not enclosed in a succulent fruit.
Can become quite invasive in the understorey of coastal forest and woodland. Seed is long-lived (3-5 years or more) in the soil, and germination is likely to be stimulated by fire. Plants also re-sprout from the roots after fire.

Dispersal:
Seed in dumped garden waste, in water and in contaminated soil. Sometimes by animals.

Look-alikes:
Some species of native Senna occur on the south coast, but are not common. Senna aciphylla prefers rocky sites, while Senna odorata grows in eucalypt forest and on rainforest margins. These two species have 8-13 pairs of leaflets with glands between all leaflet pairs. Senna clavigera occurs on rainforest margins north from Shoalhaven. It has a single gland where the leaf joins the stem, and 4-7 leaflet pairs.
Two common native found in disturbed locations similar to cassia are shrubby spurge (Phyllanthus gunnii) and coffee bush (Breynia oblongifolia). The leaves of these shrubs are similar in size and shape to the leaflets of some cassias, but are not compound, although they may appear so. The tiny flowers hang under the branches from each leaf axil, and are followed by green, red to black berries. These plants often behave in a weedy way, germinating profusely. Adult plants are less commonly seen than seedlings.
Austral indigo (Indigofera australis) is also slightly similar, in having compound leaves. However, its leaves are smaller and thinner textured than those of cassia species (each leaflet to about 2cm long), and lack glands. Indigo belongs in the pea family, and has purple sprays of pea flowers in spring, followed by small cigar-shaped pods only 2-4.5 cm long by about 3mm wide.

Control:
Cut and paint, hand-pull or dig. The whole root system needs to be removed, to avoid re-sprouting. Check for new seedlings periodically, especially after fire.