RICHES AND DISHES

Photo caption: Oenanthe crocata hemlock water-dropwort (public domain image from our digital library).

A warning in a seed catalogue that no seed or plant should be eaten unless you are absolutely certain what it is and that it would not poison you, remined me of my days in early botanical study when I dabbled in economic and medical botany. It is true that many plants have evolved to develop poisonous, injurious or foul-tasting secondary metabolites to deter animals, from the tiny to the huge, from eating them. Some of these toxins such as those in the roots and stems of the infamous hemlock water-dropwort Oenanthe crocata or ricin from the castor oil plant Ricinus communis can be lethal to humans, the former common by water and the latter many grow as an ornamental.

Plants are chemical factories and humans have known since prehistoric times that many of these chemicals have health benefits, even sometimes the poisonous ones in small or chemically modified doses. Passed on by savants of various descriptions by word of mouth and then in elaborate and voluminous (and fascinating) herbals, an extraordinary library of plant lore evolved, morphing into evidence-based science that continues to separate myth from factual data. Medical drug development would never have taken off if it were not for the secondary metabolites of plants. We humans don’t just benefit directly, Kew are running an Ethnoveterinary Medicine Project to gather information on wild plants used to treat animals. The current (well, 2018) revenue value of the world pharmaceutical industry, most of which has been derived from, and much of which still depends on, plants, is over 1.2x10⁹ US dollars!

Then, moving to food rather than drugs, there are all those plant species that we eat, whether their leaves, roots, seed, flowers, fruit or whatever. I remember that one of the greenhouses at what is now the University of Worcester, where I both studied and lectured several decades ago, was given over to economic botany. It was not widely known amongst the students, but here you could see coffee, citrus fruits, tea, bananas, sugar cane, rice, spices and many other exotic plants rather than just their products processed and packaged in the canteen, shops or in the home. I found it fascinating. 

I recently wrote about the concerns over the loss of wild relatives of crop plants but the wider problem is the worldwide crisis we have of species extinction generally. If we continue to ignore the botanical destruction that is resulting from climate change, the firing of rain and other forests, herbicide- and pesticide-based intensive agriculture, soil erosion, desertification and the harming of our oceans with concomitant damage to sea-grasses (Posidonia spp.), eel grasses (Zostera spp. mangroves and other marine halophytes, we are asking for serious trouble – and unless there is rapid change on a global scale, trouble we shall get! We are in danger not only of impoverishing the botanical marvels of our world, but of losing species before we even know what they are or how they might benefit our medicine or nourishment.

Horrifying public domain satellite image of Amazon forest fires burning (orange) in August 2019. This terrible and shameful destruction of biodiversity and the environment of forest peoples continues unabated.

Betts Ecology promote a rich botanical environment and we aim to support the most diverse botany we can in all the habitats we own or manage.

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