IS IT EDIBLE? - An introduction to Australian Bush Tucker
How can you tell whether a plant is edible or poisonous? It is not easy, unless you know that it is a particular species and that species is edible. A third or more plants in your average garden are poisonous, and it is not unreasonable to assume that a similar proportion of Australian native plants may be toxic. Some plants contain toxins that are destroyed through cooking or some other treatment. Other plants contain parts that are edible, and other parts that are poisonous. There are yet other plants that contain very low levels of toxins that the body can cope with, provided you do not eat large quantities of that plant.
Some plants may be edible, but they are not palatable (they do not taste good). If you observe animals eating a plant (eg. fruit or berry), this can indicate that this is an edible plant but such an observation can never be seen as an acid test. There are plants that animals eat, which can still be toxic to humans.
Unfortunately, we are unable to glean too much information about edible native Australian plants from Aboriginal culture due to the fact that much of this knowledge was lost following the invasion of Europeans. This was largely as a result of poor record keeping, discrimination against Aboriginal people, and the widespread destruction of Aboriginal culture. Of those records which do exist, many are derived from single sources and are often unreliable. They typically also lack refined detail such as how to prepare these plants for safe human consumption. Add to this the fact that Aboriginals did not single out specific plants for their yield as food crops and you can begin to see that our knowledge of bush tucker is not what it could be.
There are, of course, some natives which have become successful food crops, such as the macadamia nut. When examining any plant for its potential as a food source an understanding of the potential hazards of toxicity is paramount.
Native Plants to be Cautious With
Although there are tests which can be conducted to assess a plant’s level of toxicity there are some plants which have been identified as dangerous to the bush tucker enthusiast because they produce fruits which look tempting and often pass the taste test. Some notable ones are as follows:
Finger Cherry (Rhodomyrtus macrocarpa)
The Finger Cherry or Native Loquat is a tree which is commonly found in rainforests of the wet tropics. It has large glossy leaves and produces large clusters of bright red oblong fruit. When the outer covering of the fruit is removed and the flesh inside is eaten it tastes exceptionally good.
However, there are reports of people who have eaten sufficient quantities of this fruit who have gone permanently and incurably blind. Many Aborigines report eating this fruit throughout their lives with no known side-effects, although some acknowledge that it is a game of chance even when the skins are removed and the flesh is roasted. The toxicity has yet to be explained although it is known that unripe fruits usually contain toxins to deter insects, birds etc from eating them before the seeds have fully matured. It is also possible that some fruits have a type of fungi living on the skin.
Cycads (Cycas, Lepidozamia, Macrozamia sp)
Cycads are palm like plants which produce large nuts. The nuts were eaten by early explorers and settlers but they cause violent stomach upsets and induce vomiting and diarrhoea. Cattle which feed on these plants lose their balance and eventually die. The nuts are known to contain powerful neurotoxins which effect neuronal messages within the brain.
Nevertheless, they were a staple diet of Aborigines due to their high nutritional value. They knew how to treat them and roast them to remove their toxicity. The nuts are also consumed in other South Pacific nations as well as in Japan but recent medical advances have discovered a disease known as Western Pacific Parkinsonism-Dementia or Guam Disease amongst populations which eat the nuts in their diet. It is a long-term slow acting degenerative disease which indicates that the toxins may have a cumulative effect within the body.
Native Cashew (Semecarpus australiensis)
The nuts of the exotic cashew tree, Anacardium occidentale, must be carefully prepared to remove toxicity although not many people realise this. In much the same way, the native cashew is also toxic but to a much higher degree. The area where the nut joins the apple leaks a black resinous liquid which is so abrasive that it can remove paint from cars parked beneath. If consumed it can inflame the mouth and throat and cause intestine ulcerations, but even so some people argue that it is safe to eat.
The plant itself is also known to cause contact dermatitis in people with sensitive skins and severe lesions and blisters can occur within 24 hours of contact.
Stinging Tree (Dendrocnide moroides)
This plant occurs in rainforests and is also known as Gympie-Gympie. It has a reputation for being one of the most dangerous plants but is easily recognised by the hollow needles which adorn the stems and leaves of the plant. Each needle contains a toxin and causes incredible pain when touched. The effects may last as long as a year afterwards.
The fruits themselves are edible although the bland taste may not be worth the effort collecting in light of the potential hazard of the needles. The fruit themselves are also covered in toxic hairs. The safest method of harvesting the fruit is to knock them off the plant using sticks and then handling them with thick gloves. They must then be rubbed between layers of cloth to remove the hairs. A final rubbing with bare hands will detect any stinging hairs left before eating.
Did you find this interesting, do you want to learn more? We recommend Bush Tucker Plants. This one of kind course will teacher you about Australian Native Bush Foods. This course is suitable for those with a curiosity and interest in survival in the Australian bush, those wanting to grow their own native foods and those with an interest in growing bushfoods commercially. Still not sure? Email us now or ring for a chat.