Acacia olgana
Maconochie
Fabaceae
Classification of the genus Acacia (in the wider sense) has been subject to considerable debate. It is generally agreed that there are valid reasons for breaking it up into several distinct genera, but there has been disagreement over the way this should be done. As of 2017, it is widely (but not completely) accepted that the section that includes the majority of the Australian species (including this one) should retain the name Acacia, whilst other sections of the genus should be transferred to the genera Acaciella, Mariosousa, Senegalia and Vachellia[
K- Title
- Plants for a Future
- Author
- Ken Fern
- Description
- Notes from observations, tasting etc at Plants For A Future and on field trips.
].
Racosperma olganum (Maconochie) Pedley
Common Name:
General Information
Acacia olgana is a shrub or a small tree; it usually grows up to 6 metres tall, though occasionally can reach 15 metres[
]. Although it produces true leaves as a seedling, like most members of this section of the genus, the mature plant does not have true leaves but has leaf-like flattened stems called phyllodes[
].
The plant is harvested from the wild for local use as a food.
Known Hazards
The seed of many Acacia species, including this one, is edible and highly nutritious, and can be eaten safely as a fairly major part of the diet. Not all species are edible, however, and some can contain moderate levels of toxins[
1295- Title
- Acacia in Australia: Ethnobotany and Potential Food Crop
- Publication
- Janick (ed.), Progress in new crops pp 228-236, (1996) ASHS Press, Alexandria, VA.
- Author
- Lister P.R.; Holford P.; Haigh T.; Morrison D.A.
- Website
- https://hort.purdue.edu/newcrop/proceedings1996/v3-toc.html
- Publisher
- ASHS Press, Alexandria, VA.
- Year
- 1996
- ISBN
- 0-9615027-3-8
- Description
-
]. Especially when harvesting from the wild, especial care should be taken to ensure correct identification of any plants harvested for food[
K- Title
- Plants for a Future
- Author
- Ken Fern
- Description
- Notes from observations, tasting etc at Plants For A Future and on field trips.
].
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.
Botanical References
Range
Australia - central arid belt in northern South Australia and southern Northern Territory
Habitat
Often found along watercourses, in gorges, crevices on rocky ranges, on sedimentary or conglomerate rocks, sometimes on sand dunes, in shrubland and woodland[
].
Properties
Edibility Rating | |
Medicinal Rating | |
Habit | Tree |
Height | 5.00 m |
Pollinators | Insects |
Cultivation Status | Wild |
Cultivation Details
Acacia olgana is native to the arid region of central Australia with very hot summers and occasional frosts in the cold season.
Requires a sunny position in a well-drained soil.
The seeds of most acacia species can be quickly and efficiently harvested at full maturity without the need for any specialised equipment. Small seed-bearing branches can be cut and beaten on sheets, or bushes can be beaten or shaken directly onto large sheets[
1294- Title
- Potential of Australian Acacias in combating hunger in semi-arid lands
- Publication
- Conservation Science W. Aust. 4 (3):161-169 (2002)
- Author
- Rinaudo A.; Patel P.; Thomson L.A.J.
- Publisher
-
- Year
- 2002
- ISBN
-
- Description
-
].
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[
755- Title
- Nodulation Plants in GRIN Taxonomy
- Publication
-
- Author
-
- Website
- http://www.ars-grin.gov/~sbmljw/cgi-bin/taxnodul.pl?language=en
- Publisher
- United States Department of Agriculture
- Year
- 0
- ISBN
-
- Description
- An online database listing plants that have either positive or negative reports on root and stem nodulation with nitrogen-fixing bacteria.
].
Edible Uses
Seed - cooked[
1295- Title
- Acacia in Australia: Ethnobotany and Potential Food Crop
- Publication
- Janick (ed.), Progress in new crops pp 228-236, (1996) ASHS Press, Alexandria, VA.
- Author
- Lister P.R.; Holford P.; Haigh T.; Morrison D.A.
- Website
- https://hort.purdue.edu/newcrop/proceedings1996/v3-toc.html
- Publisher
- ASHS Press, Alexandria, VA.
- Year
- 1996
- ISBN
- 0-9615027-3-8
- Description
-
]. It can be eaten in the same ways as other small legume seeds and is also ground into a powder then used as a flavouring in desserts or as a nutritious supplement to pastries and breads[
1295- Title
- Acacia in Australia: Ethnobotany and Potential Food Crop
- Publication
- Janick (ed.), Progress in new crops pp 228-236, (1996) ASHS Press, Alexandria, VA.
- Author
- Lister P.R.; Holford P.; Haigh T.; Morrison D.A.
- Website
- https://hort.purdue.edu/newcrop/proceedings1996/v3-toc.html
- Publisher
- ASHS Press, Alexandria, VA.
- Year
- 1996
- ISBN
- 0-9615027-3-8
- Description
-
]. The seedpods are 35 - 100mm long and mostly 3 - 5mm wide, with light brown, broadly oblong to broadly elliptic seeds 3 - 5mm long[
].
Acacia seeds are highly nutritious and contain around 26% protein, 26% available carbohydrate, 32% fibre and 9% fat. The fat content is higher than most legumes with the aril providing the bulk of fatty acids present. These fatty acids are largely unsaturated. The energy content is high in all species tested, averaging 1480 ±270 kJ per 100g. The seeds are low glycaemic index foods - the starch is digested and absorbed very slowly, producing a small, but sustained rise in blood glucose and so delaying the onset of exhaustion in prolonged exercise[
1295- Title
- Acacia in Australia: Ethnobotany and Potential Food Crop
- Publication
- Janick (ed.), Progress in new crops pp 228-236, (1996) ASHS Press, Alexandria, VA.
- Author
- Lister P.R.; Holford P.; Haigh T.; Morrison D.A.
- Website
- https://hort.purdue.edu/newcrop/proceedings1996/v3-toc.html
- Publisher
- ASHS Press, Alexandria, VA.
- Year
- 1996
- ISBN
- 0-9615027-3-8
- Description
-
].
The ground seed can be used to produce a high quality, caffeine-free coffee-like beverage[
1295- Title
- Acacia in Australia: Ethnobotany and Potential Food Crop
- Publication
- Janick (ed.), Progress in new crops pp 228-236, (1996) ASHS Press, Alexandria, VA.
- Author
- Lister P.R.; Holford P.; Haigh T.; Morrison D.A.
- Website
- https://hort.purdue.edu/newcrop/proceedings1996/v3-toc.html
- Publisher
- ASHS Press, Alexandria, VA.
- Year
- 1996
- ISBN
- 0-9615027-3-8
- Description
-
].
Medicinal
The bark of all Acacia species contains greater or lesser quantities of tannins and are astringent. Astringents are often used medicinally - taken internally, for example. they are used in the treatment of diarrhoea and dysentery, and can also be helpful in cases of internal bleeding. Applied externally, often as a wash, they are used to treat wounds and other skin problems, haemorrhoids, perspiring feet, some eye problems, as a mouth wash etc[
601- Title
- The Useful Native Plants of Australia.
- Publication
-
- Author
- Maiden J.H.
- Website
- http://www.biodiversitylibrary.org
- Publisher
- Turner & Co.; London.
- Year
- 1889
- ISBN
-
- Description
- 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.
,
K- Title
- Plants for a Future
- Author
- Ken Fern
- Description
- Notes from observations, tasting etc at Plants For A Future and on field trips.
].
Many Acacia trees also yield greater or lesser quantities of a gum from the trunk and stems. This is sometimes taken internally in the treatment of diarrhoea and haemorrhoids[
601- Title
- The Useful Native Plants of Australia.
- Publication
-
- Author
- Maiden J.H.
- Website
- http://www.biodiversitylibrary.org
- Publisher
- Turner & Co.; London.
- Year
- 1889
- ISBN
-
- Description
- 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.
].
Other Uses
None known
Propagation
Seed - best sown as soon as it is ripe in a sunny position in a warm greenhouse[
1- Title
- RHS Dictionary of Plants plus Supplement. 1956
- Publication
-
- Author
- F. Chittendon.
- Publisher
- Oxford University Press
- Year
- 1951
- ISBN
- -
- Description
- Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
].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[
1294- Title
- Potential of Australian Acacias in combating hunger in semi-arid lands
- Publication
- Conservation Science W. Aust. 4 (3):161-169 (2002)
- Author
- Rinaudo A.; Patel P.; Thomson L.A.J.
- Publisher
-
- Year
- 2002
- ISBN
-
- Description
-
].
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