The origin and rarity of botanical carnivory.

Most plants are strict producers: they create the biomass consumed by animals and other heterotrophs to sustain life. Occasionally, the tables are turned and the plant becomes predator and the animal prey. Botanical carnivores remind us that some vascular plants have evolved remarkable mechanisms for acquiring key nutrients. Likewise, they demonstrate the parallels between disparate life forms and show how evolution has rearranged existing characters into novel combinations to achieve new functions. But despite its obvious advantages and substantial geological history, botanical carnivory remains a minor nutritional mode, apparently because prey use is usually not the most economical way for plants to secure nutrients.