The carnivorous plant genus that uses a corkscrew-shaped trap to capture protozoa is Genlisea.
Genlisea is commonly called the corkscrew plant because its underground trapping leaves form spiraled, eel-trap-like tubes. These pale, rootless leaves branch into furrowed arms lined with inward-pointing hairs. Tiny organisms can enter but are guided deeper toward a digestive chamber, where the plant obtains nutrients such as nitrogen and phosphorus.
Unlike the familiar Venus flytrap or sundew, Genlisea generally targets microscopic prey rather than visible insects. Its traps capture protozoa and other minute soil organisms in wet, nutrient-poor habitats across Africa and Central and South America. The above-ground leaves perform photosynthesis, while the subterranean leaves handle trapping and also help anchor the plant.
Charles Darwin suspected that Genlisea might be carnivorous, but the genus’s carnivory was not demonstrated conclusively until 1998. The genus belongs to the bladderwort family, Lentibulariaceae, alongside Pinguicula and Utricularia; those relatives use sticky leaves and bladder traps rather than Genlisea’s corkscrew lobster-pot mechanism.