About CPs
The Genus Genlisea

Genlisea flowers
Genlisea flowers.

Genlisea violacea
Genlisea violacea. Notice the traps in the soil. Those are not roots! This plant has no roots.

The genus Genlisea consists of plants that grow in very wet habitats, and like the closely related Utricularia they produce their traps underwater or in water-saturated muck. The top part of the trap consists of a descending stolon. About midway down the stolon there is a swollen digestion chamber--the utricle--which makes the descending part of the stolon look somewhat like the neck of an ostrich that has eaten an overly big lump of food. Below this chamber, the stolon continues downward as a hollow tube. The tube bifurcates into two long, spiralling branches. Each branch is spirally-slit along its length. Intricate, curved hairs ensure that creatures passing through the slit find themselves in a tunnel travelling upwards, but are unable to backtrack to freedom. All they can do is progress is towards the utricle.

There are more than twenty species in the genus Genlisea, and there is a great deal that we don't understand about them. Many species produce two types of traps on the same plant--smaller ones confined to near the soil surface, and much larger ones that penetrate deeply into the soil. Are the two traps foraging for different kinds of prey? Other observations have found that the tube of Genlisea hispidula traps have some kind of mucus plug between the utricle and the trap fork. Some researchers have suggested that prey may be attracted to the traps, perhaps because of air trapped in the traps. There is some evidence that indicates Genlisea is particularly effective at trapping protozoans, although poking around in a trap with a microscope reveals many other prey items, too.

I know of no common name for these plants, but some growers call them "corkscrew plants." The Latin genus name honors Contesse Stéphanie-Félicité du Crest de Saint-Aubin de Genlis, a French writer and educator whose achievements exceed even the length of her name.

Genlisea cannot be reliably classified by a simple set of characteristics. The great expert Peter Taylor ultimately concluded that a mix of characters must be used, including the way the flower pedicels bend when in fruit, the nature of the indumentum (the hairy surface that covers the plant), and other more minor details. Genlisea identification is not for the weak-kneed. A dissecting microscope is required to do it properly.

Read more about Genlisea at the ICPS sarracenia.com FAQ

-- Barry Rice

 

Genlisea information in the Carnivorous Plant Newsletter:

Taylor, Peter (1991) The Genus Genlisea. Carniv. Pl. Newslett. 20(1-2):20-26 ( )

Taylor, Peter (1991) The Genus Genlisea St. Hil.: An annoted bibliography. Carniv. Pl. Newslett. 20(1-2):27-33 ( )

Taylor, Peter (1991) Peter Taylor line drawings. Carniv. Pl. Newslett. 20(1-2):34-43 ( )

Taylor, Peter (1991) A revised World list of the genus Genlisea St. Hil.. Carniv. Pl. Newslett. 20(1-2):59 ( )

Meyers-Rice, Barry (1994) Growing terrestrial Genlisea. Carniv. Pl. Newslett. 23(2):36-38 ( )

Rivadavia, Fernando (2001) Utricularia nelumbifolia Gardn. at Last!. Carniv. Pl. Newslett. 30(1):5-10 ( )

Search the CPN Index and Archive for over 45 articles about Genlisea.



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