Convergent Insect Eaters: Pitcher Plants

Plants that digest insects have evolved independently in several distantly related lineages, apparently as an adaptation to low-nitrogen soils.

The production of “pitchers” — tubular leaves that insects have a hard time escaping — occurs in several plant groups that until recently were thought to be closely related.

Now there is compelling evidence that they are quite separate — the pitcher plants of the New World (Sarraceniaceae) are closer to blueberries and kiwi fruits, while those of the Old World (Nepenthaceae) are related to other insectivores (the Venus fly-trap and the sundews), and in turn to knotweeds and carnations.