Prostanthera melissifolia F.Muell.

Nomenclature and Habit

Prostanthera melissifolia F.Muell., commonly known as balm mint bush, is an erect shrub that usually reaches a height of 1 to 2 meters (3 feet 3 inches to 6 feet 7 inches).

It has branches that are both hairy and glandular.

Leaf Color and Shape

Its leaves are dark green on the upper surface and paler underneath, with an egg shape.

Leaf Dimensions

The leaves measure 15 to 30 millimeters (0.59 to 1.18 inches) long and 10 to 15 millimeters (0.39 to 0.59 inches) wide, and are attached to a 10 to 15 millimeter (0.39 to 0.59 inch) long petiole.

Leaf Texture and Venation

The leaf edges have fine teeth, and the midrib and veins are covered in hairs.

Flower Arrangement

Flowers grow in clusters of 10 to 20 at the ends of branchlets.

Bracteole Characteristics

There are bracteoles 1 to 2.2 millimeters (0.039 to 0.087 inches) long at the base of each cluster, and these bracteoles fall off as the flowers mature.

Sepal Characteristics

The sepals are green, often with a maroon tint, and form a tube 2 millimeters (0.079 inches) long with two egg-shaped to oblong lobes that are 1.5 to 2.5 millimeters (0.059 to 0.098 inches) long.

Petal Color and Size

The petals are mauve, purple, or pink, and measure 10 to 12 millimeters (0.39 to 0.47 inches) long.

Petal Tube Structure

They form a bell-shaped tube 5 to 6 millimeters (0.20 to 0.24 inches) long that is divided into two lips.

Lower Lip Central Lobe

The central lobe of the lower lip is 5.5 to 7 millimeters (0.22 to 0.28 inches) long and 5 to 6 millimeters (0.20 to 0.24 inches) wide.

Lower Lip Side Lobes

The side lobes of the lower lip are 4 to 6 millimeters (0.16 to 0.24 inches) long and 5 to 6 millimeters (0.20 to 0.24 inches) wide.

Upper Lip Structure

The upper lip is 3 to 3.5 millimeters (0.12 to 0.14 inches) long and 7 to 8 millimeters (0.28 to 0.31 inches) wide, with a central notch that is 3 to 3.5 millimeters (0.12 to 0.14 inches) deep.

Flowering Period

This species flowers in spring.

Habitat and Distribution

It grows in tall montane forests, distributed between the Otway and Strzelecki Ranges in Victoria, and on the far south coast of New South Wales.