Acacia implexa
Acacia implexa
Safety & Hazards
Stock deaths have been caused by ingestion of green pods[1]. The bark contains high levels of tannins and saponins and was traditionally used as a fish poisin to stun fish so that they could be captured for eating[2]. Although poisonous, saponins also have a range of medicinal applications and many saponin-rich plants are used in herbalism (particularly as emetics, expectorants and febrifuges) or as sources of raw materials for the pharmaceutical industry. Saponins are also found in a number of common foods, such as many beans. Saponins have a quite bitter flavour and are in general poorly absorbed by the human body, so most pass through without harm. They can be removed by carefully leaching in running water. Thorough cooking, and perhaps changing the cooking water once, will also normally remove most of them. However, it is not advisable to eat large quantities of raw foods that contain saponins. Saponins are much more toxic to many cold-blooded creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish and make them easy to catch[PFAF]. Especially in times of drought, many Acacia species can concentrate high levels of the toxin Hydrogen cyanide in their foliage, making them dangerous for herbivores to eat.
Cultivation Details
Acacia implexa is a plant of the temperate to subtropical zones of eastern Australia, mainly in higher rainfall areas. It is fairly frost-tolerant when dormant, surviving short periods with temperatures falling to around -6°c[2]. The plant grows best in moister regions, cropping well in an area where the mean annual rainfall was 825, (where it attained a height of 3.1 metres and a dbh of 38mm at 2.6 years, increasing to 4.2 metres with a dbh of 44mm at 5.2 years[2]. Requires a sunny position. Established plants are reasonably drought tolerant[2]. Requires a well-drained soil, succeeding in a variety of textures even when the fertility is low[2]. Plants are tolerant of strong winds, though they are apt to become wind-shaped[2]. A vigorous, long-lived, fast to moderately fast growing species[2]. The plant responds well to coppicing, and can also sucker freely, particularly if the main stems are cut back severely or if the roots are disturbed[2]. The plant is resistant to debarking by stock[2]. This species has a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[3]. This species is often confused with Acacia melanoxylon[1].
Propagation
Seed - best sown as soon as it is ripe in a sunny position in a warm greenhouse[4].The dried seed of most, if not all, members of this genus has a hard seedcoat and may benefit from scarification before sowing to speed up germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing. Sow the seed in Spring in a greenhouse. As soon as the seedlings are large enough to handle, prick them out into individual pots and grow them on in a sunny position in the greenhouse for their first winter. Plant them out in late spring or early summer, after the last expected frosts, and consider giving them some protection from the cold for their first winter outdoors. Acacia seeds that have matured fully on the bush and have been properly dried have a hard seed coat and can be stored in closed containers without deterioration for 5 - 10 years or more in dry conditions at ambient temperatures. It is best to remove the aril, which attracts weevils and can lead to moulds forming. The arils are easilyremoved by placing the seeds in water and rubbing them between the hands, then drying the seeds and winnowing them[5]. Cuttings[2]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Acacia+implexa>
Pollinators
Insects
References
- [1]Flora of Australia — http://www.anbg.gov.au/abrs/abif/flora/ ↩︎The full information from the Flora of Australia - on-line. An excellent resource.
- [2]Acacia Search; Evaluation of Acacia as a woody crop option for Southern Australia — Maslin B.R. & McDonald M.W. · Rural Industries Research and Development Corporation; Western A · 2004 · ISBN 0642 58585 7 ↩︎
- [3]Nodulation Plants in GRIN Taxonomy — United States Department of Agriculture · http://www.ars-grin.gov/~sbmljw/cgi-bin/taxnodul.pl?language=en ↩︎An online database listing plants that have either positive or negative reports on root and stem nodulation with nitrogen-fixing bacteria.
- [4]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [5]Potential of Australian Acacias in combating hunger in semi-arid lands — Rinaudo A.; Patel P.; Thomson L.A.J. · 2002 ↩︎
- [6]The Useful Native Plants of Australia. — Maiden J.H. · Turner & Co.; London. · 1889 · http://www.biodiversitylibrary.org ↩︎Terse details of the uses of many Australian plants and other species naturalised, or at least growing, in Australia. It can be downloaded from the Internet.
- [7]Native Tastes of Australia — http://tasteaustralia.biz/ ↩︎A website with detailed information on around 50 species of native Australian food plants, including recipes.
- [8]Phytochemical Profile and Antibacterial and Antioxidant Activities of Medicinal Plants Used by Aboriginal People of — Akter K. et al · 2016 · http://dx.doi.org/10.1155/2016/4683059 ↩︎
- [PFAF]Plants for a Future — pfaf.org ↩︎