pitcher plant

Pitcher plants are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap. It has been widely assumed that the various sorts of pitfall trap evolved from rolled leaves, with selection pressure favouring more deeply cupped leaves over evolutionary time. However, some pitcher plant genera (such as Nepenthes) are placed within clades consisting mostly of flypaper traps: this indicates that this view may be too simplistic, and some pitchers may have evolved from flypaper traps by loss of mucilage.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 occur in locations where the soil is too poor in minerals and/or too acidic for most plants to be able to grow.
The families Nepenthaceae and Sarraceniaceae are the best-known and largest groups of pitcher plants.
The Nepenthaceae contains a single genus, Nepenthes, containing about 120 species and numerous hybrids and cultivars. In these Old World pitcher plants, the pitchers are borne at the end of tendrils that extend from the midrib of an otherwise unexceptional leaf. The plants themselves are often climbers, accessing the canopy of their habitats using the aforementioned tendrils, although others are found on the ground in forest clearings, or as epiphytes on trees.
Sarraceniaceae is a family of pitcher plants (along with Nepenthaceae), belonging to order Ericales (previously Nepenthales).These plants grow in nutrient-poor, often acidic soil and use the insects as a nutritional supplement. The pitchers originate from a rhizome and die back during the winter dormancy. Plants of the genus Sarracenia occur mostly in sphagnum bogs.
There are several species of American pitcher plants, most having tall, narrow pitchers that are vertical or nearly so. The Purple pitcher plant, however, has short, squat, bulbous pitchers close to the ground, and the Parrot pitcher plant has pitchers that grow horizontally.