The Eremophila Page Background Propagation Cultivation Eremophila Seed Germination Some Selected Species The Eremophila Study Group Further Information Guide to Australian Plants SGAP Home Page Background Eremophila is a genus of 214 species which are commonly called "emu bushes". All species are endemic to Australia and they are generally plants of semi arid to arid regions. They occur in all mainland states. The plants produce fleshy fruits which are often eaten by birds and animals. The common name derives from the erroneous belief that the fruits are commonly eaten by emus and that the chemical changes that occur in the seed during digestion enhance the rate of seed germination after excretion. In fact, the fruits of relatively few species are eaten by emus and the time of passage through a bird is insufficient to influence germination. The plants are also known as "poverty bushes" because of the ability of many of them to survive in very dry, inhospitable environments. The foliage of some species is toxic and stock poisonings have occurred (eg. E.freelingii, E.latrobei). Some other species are useful as fodder plants (eg. E.bignoniiflora, E.oppositifolia). Eremophilas have also been valued for medicinal and cultural purposes by Aboriginal people. For example, E.longifolia was important to the Adnyamathanha people of the northern Flinders Ranges, as reported by Rosemary Pedler in the Eremophila Study Group Newsletter, December 1994: A very common and widespread species, it was of considerable importance to them. The foliage was used to cover the dead before burial which did not take place immediately after death. The relatives would visit the dead person from time to time to observe what was happening to the covering leaves, and there was significance in the way in which the leaves lay. The body was buried at a depth of about an arm's length after about a month and was again laid on and covered by the Varti-varka foliage (Eremophila longifolia). Also used for medicinal purposes, the bark of trunks was scraped off, reduced to ash and then mixed with emu oil. This preparation was then used for all manner of skin complaints with excellent results, according to several people in the group. This is still being used today. I was also told by one of the men that the smoke from Varti-varka was used in the initiation ceremony of young boys. This aspect is in the past as the last fully initiated Adnyamathanha man is very elderly now. Characteristics Eremophila is a genus in the plant family Myoporaceae which takes its name from the genus Myoporum. They are usually small to medium shrubs although a few may be large shrubs or small trees (eg. E.bignoniiflora). Those species which occur in the harshest of climates have developed methods to cope with the severe conditions. Many have greyish, hairy foliage which reflect the sun's rays while other have a shiny, sticky coating on the foliage as a protection against drying winds. The flowers are more or less tubular in shape with upper and lower lips. They are reasonably large and often very colourful and are sometimes spotted. In some species the corolla may also be subtended by a large and attractive calyx. These features have resulted in a number of species being cultivated as ornamental plants in suitable climates. Flowers occur in the leaf axils. The flowers contain nectar and are frequented by honey-eating birds or insects. Following flowering, 1 to 12 seeds develop in a fleshy or dry indehiscent fruit. Propagation Most emu bushes are propagated by cuttings or other vegetative means (such as grafting) as the seed can be difficult to germinate reliably. Seed Although it is possible to achieve germination of Eremophila seeds by sowing the fruits whole, this gives very inconsistent results. Extraction of the seeds from the fruits prior to sowing is far more effective but this is time consuming, requires considerable practice to avoid damage to the seed and, even then, reliable germination may depend on other factors such as the age of the seed, the possible presence of inhibitors and temperature. The most effective method of releasing the seeds is to split the woody fruit in such a way as to open the cells containing the seeds. This requires a sharp blade and some seeds will be unavoidably damaged by the process. Extracted seed usually germinates well by conventional sowing methods in a standard seed raising mix. In some cases it has been found that removal of the testa from the seed (the thin, skin-like coating surrounding the seed) improves germination. There appears to be conflicting evidence on the influence of the age of the seed on germination. Further information on experiments on the germination of Eremophila seed can be found in A Study of Eremophila Seed Germination by Paul Rezl. Cuttings Many eremophilas strike readily from cuttings of hardened, current season's growth. Cuttings about 75-100 mm in length with the leaves carefully removed from the lower two-thirds seem to be satisfactory. "Wounding" the lower stem by removing a sliver of bark and treating with a "root promoting" hormone both seem to improve the success rate. Grafting Many eremophilas are difficult to cultivate in humid areas but, because of their ornamental potential, many people continue to make the effort. One method which is reasonably successful is the grafting of desirable species onto hardier root stocks. Experimentation into suitable stock/scion combinations is still being carried out but the best root stocks appear to be species in the related genus Myoporum. M.parvifolium, M.montanum, M.insulare and M.acuminatumhave been used successfully with a large number of Eremophila scions and the procedure has certainly improved the hardiness of many of those species. General Propagation Further details on general plant propagation can be found at the Society's Plant Propagation Pages. Cultivation Although mainly grown by Australian plant enthusiasts, emu bushes have considerable potential for more general cultivation, particularly in areas with relatively dry summers. Once established they are very drought tolerant and rarely require artificial watering. With many different forms, growth habits and flower colours, eremophilas can be used for many different purposes in the garden. In addition, the flowers of many species produce nectar and are excellent for attracting birds. In cultivation all species perform best in well-drained soils and rarely succeed in continually wet soils. Shallow clay soils can present problems but if garden beds are built up to 300-600mm, greater success is experienced. Many species tolerate alkaline soils. Eremophilas are generally at their best in open, sunny positions with good air circulation (ie. not crowded by adjacent plants. Many species are adaptable to humid climates but those species with hairy foliage may be subject to fungal diseases is those areas and are best avoided. Emu bushes are not demanding as far as fertilizing is concerned but they do respond to applications of slow release fertilizer applied after flowering. If desired, the plants can be pruned back by about one third after flowering to promote a bushy habit of growth. Some Selected Species 1. Eremophila debilis (fruit) The small fruits of Eremophila debilis, which is sometimes called "winter apple" [30k]. 2. Eremophila macdonnellii 3. Eremophila maculata Eremophila maculata, the "spotted emu bush", is the most commonly cultivated species. It occurs on flood plains and is tolerant of wetter conditions than most Eremophila 4. Eremophila psilocalyx Eremophila psilocalyx, is not often cultivated but makes a spectacular garden shrub 5. Eremophila racemosa Eremophila racemosa is a very rare species in its natural habitat [26k]. The Eremophila Study Group A booklet called "The Study Group Newsletters 1972 - 1985" was produced in 1991. It is an edited collection of the Group's newsletters over that period and costs $AUS8.75 posted within Australia. The Study Group was also jointly responsible for the production (in 1997) of "Eremophilas for the Garden", a small book describing around 70 species with text and photographs. This book costs $AU11.50 posted within Australia. Both publications can be obtained from Colin Jennings, 4 Kinnaird Crescent, Highbury, South Australia, 5089. Postage to overseas locations would be at cost. Most books dealing with Australian native plants will contain useful information on the botany and horticulture of eremophilas. Some of the most detailed references are listed below. •Elliot, R and Jones D (1984), The Encyclopaedia of Australian Plants, Vol.3, Lothian Publishing Company Pty Ltd, Melbourne. •Richmond G and Ghisalbertii E (1994), The Australian Desert Shrub Eremophila (Myoporaceae): Medicinal. Cultural , Horticultural and Phytochemical Uses, Economic Botany 48(1): 35-59, 1994. •Society for Growing Australian Plants - South Australian Region (1997), Eremophilas for the Garden, SGAP (SA Region). Several issues of the Society's journal "Australian Plants" are particularly useful for those interested in Eremophila. •Vol 12, No.93 December 1982; Numerous articles on botany, propagation and cultivation. •Vol 12, No.100 September 1984; Eremophila in Hobart. • Vol 13, No.103 June 1985; Eremophila in Alice Springs. •Vol 15, No.120 September 1989; Cultivation and propagation of Eremophila in Sydney. • Vol 17, No.134 March 1993; Eremophila germination studies. [ SGAP Home Page ] [ Return to Index ] Updated: Thursday 18 December 1997 by Brian Walters (sgap@ozemail.com.au).