Nutrition of carnivorous plants has rarely been studied in dry-soil species with long, deep roots, with the focus hitherto on shallow-rooted genera from boggy soils. Paniw et al. assess the role of leaf (via fly feeding) and root (via soil fertilizer) nutrient uptake in growth promotion of Drosophyllum lusitanicum.
Insect feeding significantly promotes growth, with no additive effect of soil fertilisation. A strong reliance on insect feeding in a carnivorous plant with well-developed roots is here quantified for the first time, challenging the prevailing cost-benefit hypothesis of the evolution of plant carnivory.