A shrub to 2 metres tall by up to 1 metre wide.
It is found in semi-arid and arid regions of NSW, on the western plains and far-western plains, west from around Condoblin and Nyngan, extending west, over the border into South Australia. This species continues into the Northern Territory and Western Australia.
It typically grows in arid shrublands and woodlands, on skeletal rocky soils.
Prostanthera have simple, opposite and usually odorous leaves. In this species, In this species, leaves are narrow-ovate to narrow-elliptic, to 30 mm long and 10 mm wide, bright green and aromatic, and covered with glands.
Flowers have a shape described as labiate (applied to all Lamiaceae flowers) with petals varying in their size, purple to lilac, produced in leaf axils. One of the identification features for Prostanthera is that the 5 calyx parts (sepals; basal whorl of the flower) are fused into 2 lips. In this species, flowers are produced in leaf-axils solitarily but in dense leafy clusters with flowers to 2 cm long and across, white to cream with orange blotches on the lower lobe and purple stripes in the throat. Masses of flowers are produced between August and November.
Fruits are mericarps (can be called nutlets). Four are produced produced at the base of the calyx.
Reputed to be a hardy and reliable shrub to grow; possibly provided it is not too wet.
A well drained site in full sun or partial shade is appreciated by Prostanthera striatiflora.
Tip prune plants after flowering to prevent plants becoming straggly.
In our cold climate garden, plants tolerate frosts and extended dry periods.
Best grown on a free-draining soil in a drier area of the garden.
A Prostanthera in full bloom is a magnificent sight and there are so many colours to choose from for your garden. These plants are found in all states in varied soil conditions and climate and thus while it may be a challenge to grow some species many are easy in a garden situation.
A few basic growing tips are:
• Good drainage is essential. Raised beds ensure this
• Water new plants until established, weekly or as required.
• Do not over water, as this can induce root rot and fungal infestation.
• They prefer moist root runs.
• Plant drooping is an indicator of dryness
Positioning of prostantheras as border plants or near pathways is recommended as the mint odour is released when brushed against.
Propagate from cuttings. Together with most Mint Bushes, cuttings of this species produce roots rapidly and readily.
Plants may be grown from fresh seed. However, cuttings are frequently and reliably used, usually semi-hard wood or soft tip material, which strike well in spring or autumn.
The common name refers to the shape and appearance of the flowers.
Prostanthera is a diverse group of about 100 species, endemic to Australia, occurring in all states. There are still many unresolved taxa and species complexes, with new forms regularly being found. Natural hybrids occur between several species and most species appear to be capable of hybridizing when in cultivation. NSW currently has about 52 species, some of which are species-complex and others which are threatened with extinction.
Some 80% of mints contain aromatic oils within their leaves with oil of cineole being a major component. Prostanthera sieberi, P. incisa and P. staurophylla are quite pleasantly overpowering in their exudates when crushed. Oil from the leaves of some species is distilled for use in cosmetics and as soap additives.
Likely regenerates from seed after fire, possibly after 12 months.
Prostanthera – from the Greek prosthike (προσθήκη) which translates to “addendum” (root of prosthetic), and anthir (ανθήρ) meaning anther – referring to the anthers which have an appendage of tissue.
striatiflora – Latin – referring to ‘striations’, for the striking purple lines in the throat of the white flowers.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Prostanthera striatiflora profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Prostanthera~striatiflora
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia
Ausemade – Prostanthera striatiflora profile page https://ausemade.com.au/flora-fauna/flora/striped-mint-bush-prostanthera-striatiflora/