Thursday, May 30, 2024
Plant Palette

Is my sambuca safe?

By Clive Larkman

The question ‘is a plant safe to eat?’ goes back for millennia. Some plants are obviously poisonous and can be very quick to kill. Most others range from being completely safe to eat for most people, to one or two parts being edible if processed correctly. This is much the same as eating animal products, with some being immediately toxic and others safe, even eaten raw. The Puffer Fish is a deadly fish if eaten but certain parts can be carefully removed and delicately prepared to make a fancy and rare delicacy. 

The same questions arise for plants and pets, and there is the same range of options for each type of animal. Some are quite surprising, for example plants in the Lettuce family (Lactuca sp.) are quite dangerous for many birds, and raw onions can be risky for dogs.

The next issue to review is ‘how is a plant poisonous? Is it poisonous to touch? Is it poisonous if it is eaten? Is it poisonous if it has been in contact with drinking water? This is an important question because if the plant must be consumed to be poisonous then the risk of poisoning is very low.  This discussion refers to how toxic a plant is to the average consumer. There are a multitude of nasty and rapid allergies to plants and plant products that can cause severe reactions requiring immediate intervention e.g., peanuts and peppers.

We must also understand, before questioning some of the ‘poisonous plants’ in our gardens, is what is meant by ‘poisonous’. According to the dictionary, poisonous means “causing or capable of causing death or illness if taken into the body” with reference to both things, such as plants and animals, and constituent chemicals. When taken in its broadest sense that includes a huge percentage of plants we grow, both ornamental and edible, whereas what we usually mean when we ask if a plant is poisonous, is the possibility of it causing death if consumed in moderate quantities.

The reality is many plants fall into this group but very few ever cause harm. There are far more items in the home garden that are likely to cause injury or death than any of our plants. Very few plants are instantly toxic if eaten in very small amounts, and most of the constituent chemicals that make a plant poisonous give rise to a bitter and nasty taste. Evolutionarily, it makes no sense for a plant to be poisonous if it doesn’t stop animals eating it, hence the distinctive taste and often bright colours.

There are quite a few websites that list the most poisonous plants in Australia and most will point out the chemicals in the plant that are poisonous. However, there are also a number of sites that just rewrite other lists or even make up their own based on folklore and anecdotal evidence. Many of these use common names which adds even more to the confusion.

One of the deadliest plants in Australia is Thevetia peruviana, also known as Yellow Oleander. It is in the same family as Nerium oleander, the Pink Oleander, although not in the same genus. Nerium is also poisonous, but not as bad as Thevetia, however it is easy to see why plants with the same or similar common names can cause confusion if poisoning does occur.

About a decade ago a major retailer and the Nursery & Garden Industry Australia (NGIA) published a list of poisonous plants and were talking about making it compulsory to have the words ‘Poisonous if Eaten’ on the labels. They listed chilli as a poisonous plant. When taken to task over this, as chilli is a capsicum and is barely any different from the common bell pepper, they said it was in reference to the ornamental varieties. All chillis are the same (at least when referring to the commonly grown forms) with the main variation being the levels of capsaicin. This is a poison and is widely used by police in violent situations. However, in the levels found in chillis it is not poisonous – just hot.

Another plant has suddenly started appearing in articles and questions as to whether or not it is poisonous is Sambucus spp.Or Elderflower. Yes, the bark, roots, and foliage are toxic if eaten in large quantities but the taste would stop most people from consuming enough to kill them. The flowers and berries, when cooked and processed, are not only safe to eat but are seen as having health benefits. In fact, for many of the plants that have low levels of some poisonous chemicals, when treated correctly they make healthy additions to the diet and/or good medicines.

There are just so many commonly eaten plants that have poisonous parts or require processing.  Rhubarb, potato, Warrigal greens, and cashews are just some common examples. It is for this reason that labelling plants as being simply ‘poisonous’ or ‘harmful if consumed’ is confusing at best, and dangerous at worst. If the industry feels there is a need for this sort of warning, then two things must happen. Firstly, there must be a set of simple phrases that we all agree on covering issues like those above. It must be clear and concise if the general public is to read it and understand the label warnings. Secondly, and of equal importance, it must be promoted to the public that just because a plant label does not have a warning on it, that does NOT mean the plant is safe to eat.

This issue has been bubbling around in the background for years and years. At some stage soon the industry needs to develop some guidelines – before any retailer starts dictating what is and isn’t poisonous.

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