The genus Genlisea, which is with 21 species in Africa and South America native, is the only member of carnivorous plants, which has developed this kind of traps. None of the species is to be found in both continents. In former times this fact was seen as proof for the Gondwana theory, today it is believed, that the genus Genlisea has emerged in Africa and secondary a colonisation of South America has taken place by a base form, from which the South American species have emerged.
The tropical lobster-pot traps have no roots, but they produce two kinds of leaves. On the one hand overground, small normal leaves, on the other hand so-called rhizophylls. These underground, white leaves are divided and look like a turned ‚Y‘. Both arms of the Upsilon are corkscrew-like twisted and have white, minute openings. Chemical attracted preys (especially ciliates and nematodes) get through these into a chamber system, which consists of several with each other linked chambers. Between the chambers are small tiny hairs, which allow only a movement of the prey to the next central chamber, but not into the other direction. The name lobster-pot trap derives from this morphology. At the end the preys get into a central bubble, in which the digestion takes place.