This tale relates my failure to listen and remember, and my practice of habitually cooking vegetables often in the same way to my detriment.

One vegetable from our wonderful selection of Australian native foods is Warrigal Greens. That site notes ‘the leaves are rich in oxalates, so should be blanched or cooked before eating’.

The website for Taste Australia notes ‘caution should be taken with Warrigal Greens, as the leaves do contain toxic oxates, which can be harmful if consumed in large quantities. To remove the oxates, blanch the leaves for 3 minutes or so, then rinse the leaves in cold water before using them in salads or for cooking.’

While some websites claim tiny young leaves can be eaten raw without negative consequences, I would be nervous after the experience I outline below.

It is not all bad, the vegetable has useful characteristics and can be an important addition to a diet if handled correctly. It is high in fibre, vitamin C and healthy antioxidants.

Before my friend left a bag stuffed with Warrigal Greens for me, she had explained the process that I should use before eating. It was almost as if the information went in one ear and out from the other.

When I was in a rush to make a vegetable soupy stew for an early dinner, I decided to use some of that gift of Warrigal Greens. In a pot with vegetable stock, I sliced freshly harvested potatoes from my garden, chopped crisp celery stalks and cut small button mushrooms. Through this mixture I stirred a teaspoon of sambal olek and another small dab of leatherwood honey. Over this concoction I sprinkled frozen corn kernels. Meanwhile I had removed the large older leaves from many stalks of Warrigal Greens and sliced them. I added a huge pile (in the understanding that leaves of silver beet, chard and similar plants wilt to nothing much at all) to the top of the other ingredients and cooked the soupy stew until the potatoes fell apart. Then I loved eating every mouthful. Wonderful.

An hour or so later I noticed my vision was blurring. It was something similar to a painless migraine with aura, but it was stronger and more than that. A sort of headache ensued and overlapped with the seriously blurring vision. I felt weak, almost collapsible, and somewhat dizzy. My heart was pounding, my stomach felt most unsettled and waves of nausea passed over me, and urination was frequent. As the day progressed into the evening I felt very ill and wondered if the Warrigal Greens were the problem (although at that moment I wasn’t remembering their toxic oxates). Alternatively, so many symptoms were similar to those who get a cerebral venous sinus thrombosis after the first injection of an AstraZeneca vaccination. My mind was still functioning to some extent, so I googled treatments for such a clot, and learned fluids and anticoagulants were the means to help the condition. From then on I drank a glass of water every ten or 15 minutes. On the other hand, I realised that if the Warrigal Greens were doing me harm, then flushing them out was a wise manoeuvre.

Feeling very very ill, and having made the decision not to ring a friend or the ambulance (which I can imagine some readers will think was foolish of me if I was having a stroke – yes I agree), I went to bed. If I didn’t wake up next morning I wouldn’t know. If I did wake up, then I would hope to have improved. Next morning I woke with a slight headache and slight nausea, and feeling very dry so I continued the excessive water intake.

About 24 hours after consuming the well wilted Warrigal Greens and the fluids in which they had been cooked, I suddenly felt normal. It seems I had flushed out the poisons.

This has been a significant lesson to me – to stay alert and to keep thinking about all the decisions I make.

If you haven’t cooked Warrigal Greens then I hope my story will be a lesson for you. Cook separately, then rinse and drain and don’t drink the oxalic acid loaded fluids – dispose of that fluid. Otherwise you could be in big trouble if you don’t take care. As this site notes ‘Oxalic acid is toxic because of its acidic and chelating properties. It may cause burns, nausea, severe gastroenteritis and vomiting, shock and convulsions. It is especially toxic when ingested. As little as 5 to 15 grams (71 mg/kg) may be fatal to humans. Ulcerations of the mouth (which formed a day later in my mouth), vomiting of blood, and rapid appearance of shock, convulsions, twitching and cardiovascular collapse may occur following ingestion of oxalic acid or its soluble salts. Oxalic acid can bind calcium from the blood to form calcium oxalate, which can precipitate in the kidney tubules and the brain. Renal damage may result as evidenced by bloody urine. Hypocalcemia secondary to calcium oxalate formation might disturb the function of the heart and nerves.’

Please don’t let this stop you enjoying your vegetables, and especially those of Australian native origins!