Murderous plants: Victorian Gothic, Darwin and modern insights into vegetable carnivory

Abstract

Darwin's interest in carnivorous plants was in keeping with the Victorian fascination with Gothic horrors, and his experiments on them were many and varied, ranging from what appears to be idle curiosity (e.g. what will happen if I place a human hair on a Drosera leaf?) to detailed investigations of mechanisms. Mechanisms for capture and digestion of prey vary greatly among the six (or more) lineages of flowering plants that have well‐developed carnivory, and some are much more active than others. Passive carnivory is common in some groups, and one, Roridula (Roridulaceae) from southern Africa, is so passively carnivorous that it requires the presence of an insect intermediate to derive any benefit from prey trapped on its leaves. Other groups not generally considered to be carnivores, such as Stylidium (Stylidiaceae), some species of Potentilla (Rosaceae), Proboscidea (Martyniaceae) and Geranium (Geraniaceae), that have been demonstrated to both produce digestive enzymes on their epidermal surfaces and be capable of absorbing the products, are putatively just as ‘carnivorous’ as Roridula. There is no clear way to discriminate between cases of passive and active carnivory and between non‐carnivorous and carnivorous plants – all intermediates exist. Here, we document the various angiosperm clades in which carnivory has evolved and the degree to which these plants have become ‘complete carnivores’. We also discuss the problems with definition of the terms used to describe carnivorous plants. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161, 329–356.

Underground leaves ofPhilcoxiatrap and digest nematodes

“…All three of these reasons help explain why only now has carnivory been reported in Philcoxia. The present study, and heretofore less conclusive data from other plants with sticky leaves or pitfall-like structures, seem to support the notion that "we may be surrounded by many more murderous plants than we think (19). "…”

Darwin-Inspired Learning

“…Chase et al, 2009). The empirical studies conducted in both his house, and garden, were enriched by a network of global correspondents each exploring ideas related to carnivorous plant nutrition, form and function.…”

Celebrating Darwin, the botanist

“…This was perceived with delightful horror by the Victorians, and insect eating, motile plants have had a similar appeal to people as Gothic stories about vampires, ghosts and werewolves, even until today. Chase et al. (2009) review research from the time of Darwin and assess the carnivorous status of the plants discussed by Darwin and other researchers since.…”

“…In addition to his most famous treatises, notably in evolutionary biology, he laid the foundations for modern research on a range of topics including biogeography (Carlquist, 2009), physiology (including plant growth hormones and action potentials; Edwards & Moles, 2009), genetics (Pickersgill, 2009), reproductive biology (Micheneau et al. , 2009; Owens & Miller, 2009; Weller, 2009) and carnivorous plants (Chase et al. , 2009).…”