Pitcher plants of the family Sarracenia are native carnivorous plant found in bog habitats throughout the Southeastern United States. The plants prey-trapping mechanism features a deep cavity (pitcher) filled with liquid known as a pitfall trap.
Whatever their evolutionary origins, 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 sides of the pitcher are slippery and may be grooved in such a way so as to ensure that the 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.
New World pitcher plants (Sarraceniaceae), which comprise three genera, are ground-dwelling herbs whose pitchers arise from a horizontal rhizome. In this family, the entire leaf forms the pitcher, whereas in the Nepenthaceae, the pitcher arises from the terminal portion of the leaf. The species of Heliamphora, which are popularly known as marsh pitchers (or erroneously as sun pitchers), have a simple rolled-leaf pitcher, at the tip of which is a spoon-like structure that secretes nectar. They are restricted to areas of high rainfall in South America. The North American genus Sarracenia are the trumpet pitchers, which have a more complex trap than Heliamphora, with an operculum, which prevents excess accumulation of rainwater in most of the species. The single species in the Californian genus Darlingtonia is popularly known as the cobra plant, due to its possession of an inflated "lid" with elegant false-exits, and a forked "tongue", which serves to ferry ants and other prey to the entrance of the pitcher. The species in the genus Sarracenia readily hybridise, making their classification a complex matter.
In spring, pitcher plants flower while putting up their new pitchers. The flowers are quite unusual in appearance.
