1 July 2020updated 29 Jul 2021 7:05am

In a small flat with no garden, I became entranced by tropical and dangerous houseplants

I was careful, when handling Dieffenbachia, not to get any of its juice on my hands. Had I done so, I would have paid a severe penalty for my carelessness.

By John Burnside

Back in the 1980s, I worked, briefly, for a Surrey garden centre. The job was straightforward – almost soothingly routine, in fact – but it got more exciting whenever a delivery van arrived with the latest plant orders. I lived in a small, third-floor flat, and I had no garden, but the houseplants entranced me. I spent far too much of my meagre salary on exotics, ferrying them home carefully in the basket of my hand-rebuilt Dawes pushbike, and keeping them alive through a mix of painstaking care and sheer willpower.

A favourite was a native of the southern Americas, with a range that extends from Brazil to the Caribbean, a dramatic statement of a houseplant named Dieffenbachia (after the German botanist, JF Dieffenbach). Of course, I knew it had a reputation for toxicity, but at that time I had no children or pets, and I was careful, when handling the stems and leaves, not to get any juice on my hands. Had I done so, I would have paid a severe penalty for my carelessness, as botanist and botanical illustrator William Hooker observed in 1823:

… at Kew, a box of these plants arrived there from Cayenne. One of the men employed to remove the individuals to the stove, incautiously bit a piece of one of them, when his tongue swelled to such a degree that he could not move it; he became utterly incapable of speaking and was confined to the house for some days, in the most excruciating torments.

Excruciating, indeed – and yet, in spite of his agonies, that incautious man was lucky. Had he ingested a little more of the juice, his tongue and throat would have become so swollen as to cause severe respiratory distress and asphyxiation.

Dieffenbachia is not the only houseplant that can cause such irritation and swelling of the tongue and mouth. Other attractive specimens that should be kept from children and dogs include oleander, Caladium, Philodendron and asparagus fern. Painful, fast-acting toxins that directly affect the mouth of a grazing animal (or curious human) create a perfect defence: the plant may lose a leaf or a stem, but the predator is quickly deterred from further consumption when its tongue swells to twice the usual size and it is fighting to breathe. Cruel, but effective.

That said, I no longer keep Dieffenbachias in the house, not just because I now have children and pets, but out of respect for a story I was told, years ago, by an old plantsman from Kew Gardens. It’s a narrative I have found myself revisiting several times over the past few weeks, as a reminder, if such were needed, of both the historical and the continuing brutality casually visited upon native or subject peoples. The plantsman’s tale is simple, barely a story at all, but it reveals one sickening legacy of racism that still reverberates today and it explains the common name for Dieffenbachia: dumb cane.

It seems that, on the West Indies sugar plantations, enslaved people were kept in line by being forced to ingest the toxic juice of the plant, a sadistic “punishment” that might render the agonised victim speechless for days, or even lead to suffocation. The horror of that slow death is painful to imagine and it is hard not to succumb, here, to a sense of plus ça change. In truth, it is not the dumb cane that is at fault, but the frightening realisation that one person, any person, in power can brutalise another just for “talking out of turn”.

Next week: Stefan Buczacki on gardening