
Acacia omalophylla
Acacia omalophylla
Safety & Hazards
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 omalophylla is native from the temperate to the subtropica zones of eastern Australia, growing in moist to arid regions. In Queensland it is found in regions where the mean annual rainfall is within the range 500 - 626mm[1]. It the south of its range it can experience several frosts a year. Requires a sunny position. This species is found in the wild on clay and clay-loam soils[1]. The smell of the tree when in flower is abominable, and just before rain almost unbearable, and on this sign people frequently foretell the approach of rain. There have been stories of men who were employed in cutting down a tree of this species and who became so sick as rain approached that they were compelled to leave the tree[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]. Closely related to Acacia melvillei which has broader pods with transverse seeds, generally larger flower-heads and commonly broader phyllodes[4].
Propagation
Seed - best sown as soon as it is ripe in a sunny position in a warm greenhouse[5].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[6]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Acacia+omalophylla>
Pollinators
Insects
References
- [1]Grassland Species - Profiles — http://www.fao.org/ag/AGP/AGPC/doc/Gbase/Default.htm ↩︎Terse information on over 650 species of plants that grow in grassland, including trees, shrubs and perennial plants as well as grasses. Gives a brief description of the plant, its range and habitat and some of its uses.
- [2]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.
- [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]Flora of Australia — http://www.anbg.gov.au/abrs/abif/flora/ ↩︎The full information from the Flora of Australia - on-line. An excellent resource.
- [5]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 ]).
- [6]Potential of Australian Acacias in combating hunger in semi-arid lands — Rinaudo A.; Patel P.; Thomson L.A.J. · 2002 ↩︎
- [7]Vegetable Gums and Resins. — Howes. F. N. · Faber · ISBN 81-88818-17-8 ↩︎A very good book dealing with the subject in a readable way.
- [8]A Manual of Indian Timbers. — Gamble. J. S. · Bishen Singh Mahendra Pal Singh · 1972 · ISBN - ↩︎First written in the 19th century, but still a classic, giving a lot of information on the uses and habitats of Indian trees. Not for the casual reader.
- [PFAF]Plants for a Future — pfaf.org ↩︎