Carnivorous plants are plants that derive some or most of their nutrients (but not energy) from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs and rock outcroppings. Charles Darwin wrote Insectivorous Plants, the first well-known treatise on carnivorous plants, in 1875.
Carnivory include about 630 species that attract and trap prey, produce digestive enzymes, and absorb the resulting available nutrients.
A Venus flytrap snaps shut if its tiny hairs are brushed twice.
A Venus flytrap snaps shut if its tiny hairs are brushed twice.
Many of the world's 675-plus carnivorous species set passive traps. A bun-size butterwort bristles with gluey hairs that ensnare insects until digestive juices do their work.
Thirsty bugs are drawn to what look like dewdrops on an Australian sundew, then find themselves entangled in sticky tentacles.
Like figures in a shadow theater, silhouettes of prey show through a Philippine pitcher plant. The waxy surface in the red tube stops bugs from climbing free. Below, enzymes leach nutrients from trapped insects.
To avoid capturing and consuming prospective pollinators, pitcher plants keep their flowers far away from their traps via long stalks.
Blooms hang upside down like Chinese lanterns, luring bees into an elaborate pollen chamber.
Size doesn't ensure success. If a gluey tentacle grabs too little of a big fly, the bug may suffer injury but still struggle to freedom. In the realm of carnivorous plants, says William McLaughlin, curator at the United States Botanic Garden, "some insects aren't digested but are still victimized."
Largest of its kind, the South African king sundew unfurls. Leaves of this florid species can reach two feet in length.
The thimble-size west Australian pitcher plant has a taste for insects that crawl. Its guide hairs and cloying scent encourage ants to clamber into its digestive depths.
A water-filled North American hybrid tempts bees with the promise of nectar and a rim that looks like a prime landing pad. Carnivory is not the most efficient way for a plant to secure nutrients, but it is certainly among the most exotic.