pitcher plant, any of several insectivorous plants with leaves adapted for trapping insects. Each leaf forms a "pitcher," a somewhat trumpet-shaped enclosure, usually containing a liquid. An insect that enters, lured by nectar and sometimes by brilliant coloration, is prevented from retreating by deflexed bristles and ultimately is drowned in the fluid. The trapped insects are apparently digested by plant enzymes and perhaps by bacteria present in the collected rainwater solution. There are three families of pitcher plants. The American family (the Sarraceniaceae) comprises three genera of bog plants, Sarracenia of E North America, Darlingtonia of N California and adjacent Oregon (the single species is D. californica), and Heliamphora of N South America. The common pitcher plant, or side-saddle flower (S. purpurea), is found in bogs from Labrador to Florida and Iowa. The Nepenthaceae, an Old World tropical family, ranging from China to Australia and Pacifica and found chiefly in Borneo, consists of the single genus Nepenthes. Many of its species and hybrids, sometimes also called monkey cups, are cultivated as novelties for their large and showy pendent pitchers. The Australian pitcher plant (Cephalotus follicularis) is the single species of the family Cephalotaceae. The bottom leaves of its low rosette are modified into brightly colored, slipper-shaped receptacles with lids and teeth. Other insectivorous plants include the bladderwort, butterwort, Venus's-flytrap, and sundew.

Any carnivorous plant with pitcher-, trumpet-, or urn-shaped leaves. Several families include pitcher plants: Nepenthaceae (Old World pitcher plants), Cephalotaceae, Asclepiadaceae (milkweed family), and especially Sarraceniaceae (New World pitcher plants, particularly those in the eastern North American genus Sarracenia). Pitcher plants inhabit bogs, swamps, wet or sandy meadows, or savannas where the soils are water-saturated, acidic, and deficient in nitrates or phosphates. Their unusual tubular leaves have a series of nectar-secreting glands that extend from the lip down into the interior and attract insects. Once in the plant, the prey tumbles down into a liquid pool and drowns, after which an enzyme secreted within the leaf digests it, releasing nitrates and other nutrients, which supplement the meager nutrient supply of bogs. Most pitcher plants produce pitcher-shaped, insect-catching leaves in the spring and tubeless leaves in the fall. Their flowers are showy and have an agreeable scent.

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