When will people ever learn? The warning on dieffenbachia, known in Thai as sao noi pra paeng, being a dangerous plant is going viral again. Apparently someone in India just read it and shared it with her friends, then people in the Philippines and Japan picked it up and now it is making the rounds on Facebook all over again.
I understand the concern of uninformed people. Who would want “a deadly poison ... that can kill a kid in less than a minute and an adult in 15 minutes” in their midst? The warning added: “The leaf of this plant causes itching if its sap touches your skin ... It should be uprooted from gardens and taken out of offices. If touched, one should never touch his/her eyes; it can cause partial or permanent blindness."
The warning had caused many people to worry. A friend of mine cautioned her relatives not to go near the plant, despite my assurances that there was nothing to worry about.
I would be worried, too, if I had not planted, repotted and propagated dieffenbachia in its many forms over the years. I never experienced any ill effects after handling the plants with my bare hands, hence I know for sure that they pose no danger to anyone. After reading my friend’s warning not to go near the plant, I stroked the leaves of my dieffenbachia plants and then my arms and legs, to see whether it would make me feel itchy. It did not.
The warning on Facebook is accompanied by a photo of Dieffenbachia amoena. What the scaremonger probably did not know is that there are 56 species of dieffenbachia, not to mention hundreds of cultivars derived from these species. Even if Dieffenbachia amoena is destroyed in every garden, people could still be unknowingly harbouring the other species and cultivars.
Plants in this genus contain needle-shaped calcium oxalate crystals called raphides in their cells. If a leaf is chewed, these crystals can cause a temporary burning sensation and then numbing of the tongue, which gave the plants their common name, dumb cane. However, despite the bad publicity they are getting, no one is known to have actually died from accidentally ingesting the plant. To die from it, one probably has to eat a substantial amount.
My husband, ML Charuphant, a retired professor of horticulture at Kasetsart University, said ingesting a piece of dieffenbachia stem could temporarily thicken the skin and make it numb. He recalls that when he was young his family lived in a camp of the Royal Thai Army’s Ordnance Department, where his late father was an officer, near Saphan Daeng in Bang Sue. “There was a boxing camp nearby,” he recalled, “and before a fight some boxers would come to our house and ask for a stem of Dieffenbachia picta, which we grew in our yard.
Safe, but not for consumption: Like other members of the Araceae family, aglaonema and caladium have calcium oxalate crystals in their cells.
“They would take a piece about one cubic centimetre in size, wrap it in tamarind pulp and then swallow it. After a while, the skin would thicken so that the boxer could not feel pain during the fight.”
The tamarind pulp, he said, prevented the dumb cane from getting in contact with the tongue or larynx. After the fight, the boxer would drink a lot of water to purge the poison out of his system. However, do not try this at home whether you are a boxer or not.
Dieffenbachia are not the only ones which have calcium oxalate crystals in their cells. Calcium oxalate is present in most, if not all, members of the Araceae family of plants, which comprises 110 genera and 1,800 species, including aglaonema, alocasia, anthurium and caladium. As Thai plant enthusiasts well know, countless hybrids of aglaonema and caladium have been developed. Are we going to bar all these beauties from our gardens, too?
Plants in the Araceae family are not the only ones we must be wary of. Palm expert Ken Banks wrote from Hawaii to add cycads to the list of poisonous plants (Green Fingers, May 31). “The whole group are also highly toxic,” he wrote. “Every part of these plants contains a potent neurotoxin that can cause a range of problems, including death. I’ve heard that professional growers wear breathing gear when working with the pollen.
“Years ago, in Hawaii, I set out a flat of seeds of Zamia furfuracea, an ornamental known in Thai as prong mek Maxican, to dry before propagation. Sadly I left them low enough to the ground that my very young puppy got into them and ate a few. He was severely poisoned, going into convulsions on the floor of the veterinary clinic. The vet had never heard of cycad poisoning and had to call a national hotline to find out about it.
Don’t eat: ‘Dieffenbachia amoena’, left, and just some of the many dieffenbachia varieties.
“After three days in the clinic, the vet sent him home, presumably to die. He was the most pitiful sight I’d ever seen, and almost helpless. But he was tougher than the vet thought, and with a lot of love and nurturing, I brought him back to health. Nonetheless, the neurological effects dogged him his whole life.”
I have said it before and will say it again. At least one third of ornamental plants are poisonous, but even the most toxic also have medicinal benefits. Gardeners are completely safe if they are not in the habit of tasting ornamental plants. If, by accident, your skin gets in contact with the sap while potting them, all you have to do is wash the skin immediately in running water. And train your children and pets not to eat plants. n
Email nthongtham@gmail.com.
