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Growing Native Plants |
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The highland shrub Prostanthera teretifolia belongs to the Lamiaceae family and so is related to lavender and rosemary.
It occurs naturally on granite outcrops in the uplands of the New England region of New South Wales, within 50 km of Torrington, notably near Bismuth, Silent Grove and Tungsten. Here the upright, sticky-leaved shrub is found growing profusely among huge rock outcrops in association with a host of other flowering shrubs. Usually it grows to 1 m in height and may reach 2 m in rock crevices.
The
species forms an attractive bushy shrub in cultivation; the crowded greyish
foliage contrasting well with the purplish flowers. The leaves are terete (cylindrical)
up to 2 cm long, they taper at the end and sometimes have one or two lateral
lobes. They are greyish, have a distinct smell of turpentine and are arranged
in opposite pairs along the stems.
The five-lobed flowers have a flattened, funnel shape and are 2.5 cm wide with the style protruding. They appear in September and their colour can vary from pale violet to royal purple with the throat of the flower being darker.
Prostanthera teretifolia is propagated from semi-hardwood cuttings, 5-10 cm long, treated with a hormone solution. They should form roots in two to six weeks. For plants intended for heavy soils, grafting on to a small form of P. lasianthos is sometimes recommended.
In cultivation the shrub grows well, preferring a well-drained soil. This may be achieved by raising the existing soil level by at least 30 cm using mounds or retaining walls. P. teretifolia will tolerate moderate shade to full sun and is frost-hardy. Tip prun-ing after flowering and the addition of a complete fertiliser in late spring and early summer will increase vigour and promote greater flowering.
The only recorded problem with P. teretifolia is attack from soil borne fungi, like Phytophthora cinnamomi, which infect most Prostanthera species. This problem can be avoided by grafting susceptible plants on to resistant root-stocks such as Westringia.
Text by Stuart Donaldson, ANBG (1986)
Look here for a glossary of botanical terms.
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Name meaning: Prostanthera teretifolia Prostanthera - from the Greek, prostheke, an appendage and antheros, anther, referring to the spur-like appendage to the anthers; teretifolia - from the Latin, teres, rounded and folium, leaf, referring to the cylindrical leaf of this species. |
