About Boronia thujona Penfold & M.B.Welch
Boronia thujona is a glabrous shrub or small tree that reaches 1 to 4 meters (3 to 10 feet) in height. Two distinct grooves run between the leaf bases on its smaller stems. This species produces aromatic pinnate leaves, which have between 3 and 15 leaflets each. The entire leaf has an outline 30 to 80 millimeters (1 to 3 inches) long and 23 to 70 millimeters (0.9 to 3 inches) wide, attached by a 10 to 15 millimeter (0.4 to 0.6 inch) long petiole. The end leaflet is narrow elliptical, measuring 5 to 25 millimeters (0.2 to 1 inch) long and 1 to 4 millimeters (0.04 to 0.2 inch) wide; side leaflets are similar in shape but usually longer. Bright pink flowers are arranged in pairs or groups of up to six in leaf axils, with each flower borne on a 5 to 15 millimeter (0.2 to 0.6 inch) long pedicel. This species has four triangular sepals that are 0.5 to 1.5 millimeters (0.02 to 0.06 inches) long and 0.5 to 1 millimeter (0.02 to 0.04 inches) wide. Its four petals are 5 to 10 millimeters (0.2 to 0.4 inches) long, with a hairy lower surface and a small point at the tip. The eight stamens have hairy filaments, and the stigma is roughly the same width as the style. Flowering takes place from August to November, and the fruit is a glabrous capsule 3 to 4 millimeters (0.12 to 0.16 inches) long and 2 to 2.5 millimeters (0.08 to 0.1 inch) wide. This plant, commonly called bronzy boronia, grows in damp, shady forest from the Sydney region south to the Budawang Range.
