The New England Carnivorous Plant Society www.NECPS.org
The Corkscrew Plant
Genlisea
A small, terrestrial/semi-aquatic carnivorous plant, which gets its common name from the shape of its underground, twisted traps that are in the shape of a corkscrew. These long, hollow structures take the place of roots for the plant. In addition to taking up nutrients from its trapped prey, the Y-shaped traps also take up water. The leaves form rosettes on the ground’s surface, for photosynthesis, while the traps are typically underground. The traps will sprout leaves if they are exposed to light and this is useful if you are interested in propagating these plants using a trap cutting technique.
The flowers of a Genlisea occur on a tall flower scape (tall in proportion to the often diminutive plant.) The delicate flowers are often small and orchid-like. The flower colors vary from species to species. The flower structure is similar to another carnivorous plant genus called Utricularia.
How They Trap Food: Genlisea traps its prey by providing it an easy, one-way journey through the underground traps, but not providing an exit. This plant is often compared to a lobster trap; because the prey finds that it cannot exit the same way it entered the trap. Small, sharp hairs act like spikes that prevent an exit or travel back. The prey keeps moving from chamber to chamber within the trap until it reaches a final chamber (called the utricle) where it is dissolved, thus providing the nutrients to feed the plant. There are different theories as to how the plant lures its prey into the trap. One theory is that a Genlisea provides a small burst of oxygen near the entrance to a trap and the underground prey is drawn to oxygen.
Typical Prey: The corkscrew plant specializes in consuming tiny protozoans that are found underground.
Where it Lives: The corkscrew plant can be found in nutrient poor soils in tropical South America and Africa.
Basic Care: A Genlisea is not difficult grow as long as a few basic requirements are met. These plants grow in tropical climates, so the temperature where these plants are kept should stay above 60°F. They can grow well in medium to bright light, but direct sun could dry them out or scorch the leaves. They should remain wet/damp all the time and never be allowed to dry completely out. The water should be rain, distilled or reverse osmosis water so that it is mineral-free. Genlisea plants appreciate high humidity, so terrarium growing is ideal. The potting media should be nutrient-free and should incorporate some sphagnum moss for good results. It can be grown in undrained containers like many Utricularia.