Prostanthera melissifolia

Prostanthera melissifolia is an erect shrub that typically grows to a height of 1–2 m (3 ft 3 in–6 ft 7 in) and has hairy, glandular branches. The leaves are dark green above, paler below, egg-shaped, 15–30 mm (0.59–1.18 in) long and 10–15 mm (0.39–0.59 in) wide on a petiole 10–15 mm (0.39–0.59 in) long. There are fine teeth on the edges of the leaves and the midrid and veins are hairy. The flowers are arranged in bunches of ten to twenty on the ends of branchlets with bracteoles 1–2.2 mm (0.039–0.087 in) long at the base but that fall off as the flowers develop. The sepals are green, often with a maroon tinge, and form a tube 2 mm (0.079 in) long with two egg-shaped to olbong lobes 1.5–2.5 mm (0.059–0.098 in) long. The petals are mauve to purple or pink, 10–12 mm (0.39–0.47 in) long and form a bell-shaped tube 5–6 mm (0.20–0.24 in) long with two lips. The central lobe of the lower lip is 5.5–7 mm (0.22–0.28 in) long and 5–6 mm (0.20–0.24 in) wide and the side lobes are 4–6 mm (0.16–0.24 in) long and 5–6 mm (0.20–0.24 in) wide. The upper lip is 3–3.5 mm (0.12–0.14 in) long and 7–8 mm (0.28–0.31 in) wide with a central notch 3–3.5 mm (0.12–0.14 in) deep. Flowering occurs in spring.[2][3][4]

Prostanthera melissifolia was first formally described in 1858 by Ferdinand von Mueller in Fragmenta Phytographiae Australiae.[5][6]

Balm mint bush grows in tall montane forests between the Otway and Strzelecki Ranges in Victoria and on the far south coast of New South Wales.