While carnivory is a rather intuitive way to get food (after all, most of us eat meat), what may be less easily understood is why some plants became carnivorous and others did not. Environmental factors are central to solving this puzzle. Carnivorous plants grow in infertile areas, with little nutrients in the soil or water. Consequently, they have weak or nonexistent root systems and depend on other sources for nutrients, such as sunlight and
insects abundant in wet environments. Carnivorous plants without prey to catch still grow, but such starvation can inhibit special functions like flowering. Plant carnivory is such a successful strategy that it probably evolved about six times, creating widespread genera and families by the beginning of the Tertiary period (right after the dinosaurs’ demise). Now a diverse group of more than a dozen genera and 600 plant species are considered carnivorous. The many different forms that plant carnivory embodies greatly delayed botanists from accepting all variants as true carnivores.