Allocasuarina crassa (female) ALLOCASUARINA CRASSA   (Allocasuarinaceae)   By Mary King

Photographs and cultivation notes by Kris Schaffer - Neika Nursery, Hobart    

This very variable shrub or small tree has been classified as rare as it occurs only in the Cape Pillar area of the Tasman Peninsula and Tasman Island - a very rugged part of South East Tasmania, exposed to the unrelenting action of the ocean.

This endemic was first collected by Tony Moscal in 1976 and named from the latin crassus meaning “thick”. The leaves are reduced to tiny brown scale-like structures and are borne in whorls at intervals along the greenish-coloured branchlets which carry out photosynthesis - a special adaptation so that the plant can withstand periods of drought. Allocasuarina crassa is dioecious; that is there are separate male and female plants. Flowers on female trees are bright red and really showy, being 12 to 18mm (half to three-quarters of an inch) in size. Winged seeds are borne on woody cones. It tolerates a wide range of soils and conditions; will stand water-logging in winter and drought in summer.

When first offered for sale in nurseries the labels stated that Allocasuarina crassa grew 2 metres high, but it was then found that it grows much bigger with the extra water and nutrients in garden situations. And so the next lot of  labels confidently stated that this plant reaches 3 to 4 metres; now the latest ones say it will reach 6 metres! Who knows? It could grow even bigger yet!

It can have either an upright or spreading habit 3 to 4 metres across and has graceful arching branches making it a really useful subject for horticulture as it looks good either as a feature plant or in groups. Its architectural form goes well with modern buildings. Plantings near a garden lamp create a stunning effect especially after rain when the branches are spangled with water droplets.The tree responds well to pruning and the foliage is useful for flower arranging. Propagation is from seed or cuttings. If female plants are wanted, select cuttings from a female tree. 

Allocasuarina crassa (female)