About Boronia pinnata Sm.
Boronia pinnata Sm. is an erect, woody shrub that typically grows to around 1.5 metres (4.9 feet) in height. It is glabrous overall, with the only exception being its flowers. Its leaves are pinnate, bearing up to thirteen narrow elliptic to narrow oblong leaflets. The whole leaf has an outline length of 18–60 millimetres (0.71–2.36 inches) and an outline width of 14–54 millimetres (0.55–2.13 inches). Most leaflets measure 5–29 millimetres (0.20–1.14 inches) long and 1–3 millimetres (0.039–0.118 inches) wide, and are attached to a petiole 6–17 millimetres (0.24–0.67 inches) long. Flower groups, containing between three and twenty flowers (and sometimes as many as forty), grow in the leaf axils. Each whole flower group sits on a peduncle 5–20 millimetres (0.20–0.79 inches) long, while individual flowers grow on a pedicel 6–30 millimetres (0.24–1.18 inches) long. It has four triangular sepals, 1–1.5 millimetres (0.039–0.059 inches) long and around 1 millimetre (0.039 inches) wide. Its four petals are bright pink, 5–11.5 millimetres (0.20–0.45 inches) long, with a few hairs on their outer back surface. The eight stamens have hairy edges. Flowering occurs between September and January, and the fruit is a glabrous capsule 4–5 millimetres (0.16–0.20 inches) long. This boronia grows in dry forest and heath on sandstone in near-coastal areas between the Nowra district and Ballina. In horticulture, it is one of the easier boronias to grow in gardens. It performs best in a sheltered position, where rocks can support its shallow root run, and it benefits from light pruning.
