Prostanthera hindii

Mint Bush

Family: Lamiaceae

An erect shrub growing to 1 metre tall by 1 metre wide.

It is naturally confined to a small area of NSW, growing in dry sclerophyll shrubland and woodland, on shallow sandy soils, in crevices and on slopes with rocky sandstone platforms and outcrops. Occurs mainly in Wollemi National Park and Rylstone district in New South Wales (central tablelands and central western slopes divisions).

Branchlets are densely hairy and densely glandular, square to rhombic.

Leaves in opposite pairs (rarely in 3-leaf whorls), dark green above, paler below, almost glabrous, egg-shaped to narrow egg-shaped, to 25 mm long and to 8 mm wide on a petiole to 2 mm long.

Flowers have a shape described as labiate (applies to all Lamiaceae flowers) with 5 petals varying in their size, fused at their base, produced in leaf axils.
One of the identification features for Prostanthera is that the 5 calyx parts (basal whorl of the flower) are fused into 2 lips.

In this species, flowers are arranged in single leafy raceme-like groups in upper leaf axils, consisting of four to ten flowers with attached bracteoles to 6 mm long at the base. The sepals are maroon and form a tube to 3 mm wide with two lobes. The petals are to 15 mm long, fused into a tube for about half their length, mauve in colour with deep mauve to dark purple colouration inside the tube.

Flowering mainly occurs from spring to early summer

Fruits – 4 tiny nutlets (mericarps) produced at the base of the calyx.

In the garden

This species is not very well known in cultivation and sources selling this species cannot be found.

If plants could be sourced, it likely needs a well-drained sandy soil to do its best. Give a partially shady spot and tip prune after flowering to promote density, form and flowers. Could be tried in a pot.

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

Propagation

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.

Other information

There are approximately 100 species, endemic to Australia. They occur in all states.

This genus is currently under revision, and several species complexes are unresolved. Natural hybrids occur between several species and most species appear to be capable of hybridising when in cultivation.

Some 80% of mints contain aromatic oils within their leaves with oil of cineol being a major component. Prostanthera sieberi, P. incisa and P. staurophylla are quite pleasantly overpowering due to their exudates when crushed.

Positioning of prostantheras as border plants or near pathways is recommended as the mint odour is released when brushed against. Oil from the leaves of some species is distilled for use in cosmetics and as soap additives.

Most Prostanthera will regenerate from seed after fire with some species exhibiting an ability to reshoot from basal areas and stem buds. The exact response for this species is unknown.

Prostanthera – from the Greek prosthike (προσθήκη) which translates to “addendum”, and anthir (ανθήρ) meaning anther – referring to the anthers which have an appendage of tissue.

hindii – honours botanist Peter Hind (1947 – ) who, with Barry Conn (an Australian botanist and Prostanthera expert), collected the type material.

https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=gn&name=Prostanthera
http://anpsa.org.au/APOL2007/apr07-1.html
https://en.wikipedia.org/wiki/Prostanthera_hindii
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Prostanthera~hindii

By Jeff Howes, edited by Dan Clarke