Bushy shrub with erect stems and lance-shaped to inversely lance-shaped, entire, matt, grey-green leaves, to 1.5cm long. In late spring and early summer, an abundance of cup-shaped purple flowers, 1cm across, are borne in leafy, terminal racemes, 6-7cm long. 2.5m high by 1.5m wide

To cultivate: under glass, grow in a loam-based potting compost (J.I. No 2) in full light. When in growth, water moderately and apply a balanced liquid fertiliser monthly; water sparingly in winter. Outdoors, growth in moderately fertile, moist but well-drained soil in full sun. Prune lightly to keep the shape after flowering. Hard pruning could be detrimental. To propagate, take semi-ripe cuttings in summer. Prone to red spider mite and whitefly if grown under glass.

Another species of Prostanthera, P. rotundifolia, is rich in volatile oils, including menthol and cineole (as found in the mints, Mentha species). They are used externally in the treatment of colds and headaches. Presumably the leaves are infused in a bowl of hot water and the vapour inhaled.

Prostanthe’ra- Greek for prostithemi, to append or add to, prosthema, appendage; anthera, anther; in an allusion to a spur-like appendage on the back of the anther.

ovalifolia- oval, broadly elliptic foliage

An essential oil can be extracted from crushing the leaves of the species, Porstanthera rotundifolia. The leaves yield up to 0.7% of the oil. The dried leaves are also used in pot-pourri.

Probably 1,8-cineole which is the main component of the volatile oil.