The Mystery of the Genlisea
The strange structures of the Genlisea plant have long been considered a mystery. Scientists at the University of Bonn have now solved the problem: Genlisea uses water-soluble scents to lure protozoa into their underground trap and digest them. Above ground, the Genlisea is rather inconspicuous: Delicate flowers on stalks up to ten centimeters long, reminiscent of snapdragons. What makes this plant so bizarre and mysterious is underground, as the botanist Wilhelm Barthlott from the University of Bonn explains: "There is a small cauldron, a small bubble structure and at the end two little arms that are twisted like a corkscrew Small arms there are - arranged in a spiral - a series of very small openings with a kind of inward-pointing creel hair. In reality, these are not roots at all, but probably transformed leaves."
Charles Darwin already suspected over a hundred years ago that these strange structures could be used to catch prey. But there has been no proof so far, especially since nothing but a little slime could be found inside the supposed traps. The tiny openings gave Barthlott the crucial idea. The Genlisea's victims must be small enough to fit through. And they have to be digested so quickly that after half an hour nothing is left but mucus. Only single-celled organisms came into consideration: amoebas, ciliates, parameciums.
The Bonn botanists managed to prove this by feeding the Genlisia under the microscope: Parameciums can be seen swimming towards the trap openings and disappearing inside, as if magnetically attracted. There they are processed into a slimy mass by digestive enzymes in a matter of minutes. Genlisea is thus the only plant known to date that eats protozoa. And she uses a water-soluble substance to lure her victims.
