Prostanthera rhombea—Sparkling Mint–bush—LAMIACEAE

Prostanthera rhombea

Link to Images on Flickr.

Habitat—Grows in Rainforest or Sclerophyll Forest, often in gullies or riverine habitats, in sandy to sandy–loam soils over sandstone.

Distribution— Chiefly north from the Nepean River to Port Macquarie in New South Wales. Also occurs in Victoria and Queensland.

Description—Open divaricate shrub 0.5 to 2 m high, strongly aromatic; branches moderately to densely covered with stiff spreading hairs and gland–tipped hairs

Local occurrences

Comboyne State Forest

Leaves.—Simple, opposite, with prominent oil dots, lamina ± circular, usually appearing angular–ovate because margins variously recurved, 2 to 6 mm long, 1 to 5.5 mm wide; apex obtuse to rounded; base broad–cuneate to rounded; margins entire, and recurved; surfaces mid green, glabrous or sparsely covered with stiff spreading hairs and gland–tipped hairs, densely covered with ± sessile glands below; petiole 0.3 to 1 mm long.

Prostanthera rhombea
Prostanthera rhombea

Inflorescence.—Flowers axillary, part inflorescence 1–flowered; bracteoles persistent, 1.5 to 2 mm long. Calyx 4 to 5 mm long; tube 1.5 to 2 mm long; upper lobe c. 2 mm long, slightly enlarged in fruit. Corolla 7 to 8 mm long, mauve or bluish, often white apically. Anthers without appendage.

Flowering.—Mainly Spring but seen in flower in Winter.

Fruit.—A Capsule

Ripe.—Summer