Pitcher Plants

Nepenthes

Description:

Pitcher plants are several different carnivorous plants that have evolved modified leaves known as a pitfall traps – a prey-trapping mechanism featuring a deep cavity filled with liquid. Foraging, flying or crawling insects such as flies are attracted to the cavity formed by the cupped leaf, often by visual lures such as anthocyanin pigments, and nectar bribes. The rim of the pitcher (peristome) is slippery, when moistened by condensation or nectar, causing insects to fall into the trap. Pitcher plants may also contain waxy scales, protruding aldehyde crystals, cuticular folds, inward and downward pointing (retrorse) hairs, or guard-cell-originating lunate cells on the inside of the pitcher to ensure that insects cannot climb out. The small bodies of liquid contained within the pitcher traps are called phytotelmata. They drown the insect, and the body of it is gradually dissolved. This may occur by bacterial action (the bacteria being washed into the pitcher by rainfall) or by enzymes secreted by the plant itself. Furthermore, some pitcher plants contain mutualistic insect larvae, which feed on trapped prey, and whose excreta the plant absorbs. Whatever the mechanism of digestion, the prey items are converted into a solution of amino acids, peptides, phosphates, ammonium and urea, from which the plant obtains its mineral nutrition (particularly nitrogen and phosphorus). Like all carnivorous plants, they grow in locations where the soil is too poor in minerals and/or too acidic for most plants to survive.