Pitcher plant

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 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. Fact|date=May 2008 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.

Types of pitcher plants

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.

In contrast, the 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.

There are two other genera of pitcher plants, but both contain just one or two carnivorous species.

The Cephalotaceae is a monotypic family with but one genus and species, "Cephalotus follicularis". This species has a small (2 to 5 cm) pitcher similar in form to those of "Nepenthes". It occurs in only one location in southwestern Australia.

A few species of bromeliads (Bromeliaceae), such as "Brocchinia reducta" and "Catopsis berteroniana" are known or suspected to be carnivorous. Bromeliads are monocots, and given that they all naturally collect water where their leaves meet each other, and that many collect detritus, it is not surprising that a few should have been naturally selected to develop the habit into carnivory by the addition of wax and downward-pointing hairs.

The Purple pitcher plant, "Sarracenia purpurea", is the floral emblem of the province of Newfoundland and Labrador, Canada.

Further reading

* Schnell, Donald (2003). "Carnivorous Plants of the United States and Canada". Second Edition. Timber Press, Oregon, U.S.A.

External links

* [http://www.cpukforum.com/ Carnivorous Plants Enthusiast Forum]


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Look at other dictionaries:

  • Pitcher plant — Pitcher Pitch er, n. [OE. picher, OF. pichier, OHG. pehhar, pehh[=a]ri; prob. of the same origin as E. beaker. Cf. {Beaker}.] 1. A wide mouthed, deep vessel for holding liquids, with a spout or protruding lip and a handle; a water jug or jar with …   The Collaborative International Dictionary of English

  • pitcher plant — n. any of various plants with slippery, pitcherlike leaves that contain a pool of enzymes that digest trapped insects; esp., any of a family (Sarraceniaceae, order Nepenthales) of dicotyledonous, New World plants that grow in swamps and bogs …   English World dictionary

  • pitcher plant — 1. any of various insectivorous New World bog plants of the genera Sarracenia, Darlingtonia, and Heliamphora, having tubular or trumpet shaped leaves containing a liquid in which insects are trapped. 2. the common pitcher plant, S. purpurea,… …   Universalium

  • pitcher plant — noun any of several insectivorous herbs of the order Sarraceniales • Hypernyms: ↑carnivorous plant • Hyponyms: ↑common pitcher plant, ↑huntsman s cup, ↑huntsman s cups, ↑Sarracenia purpurea, ↑hooded pitcher plant …   Useful english dictionary

  • pitcher plant — noun Date: 1819 a plant (especially family Sarraceniaceae, the pitcher plant family) with leaves modified into pitchers in which insects are trapped and digested by means of liquids secreted by the leaves …   New Collegiate Dictionary

  • pitcher plant — saracėnija statusas T sritis vardynas apibrėžtis Saracėnijinių (Sarraceniaceae) šeimos augalų gentis (Sarracenia). atitikmenys: lot. Sarracenia angl. pitcher plant vok. Sarrazenie; Schlauchpflanze rus. саррацения lenk. kapturnica …   Dekoratyvinių augalų vardynas

  • pitcher plant — pitch′er plant n. pln any of various insectivorous bog plants of the family Sarraceniaceae, with hooded, pitcher shaped leaves containing a liquid in which insects are trapped • Etymology: 1810–20 …   From formal English to slang

  • pitcher plant — /ˈpɪtʃə plænt/ (say pichuh plant) noun any of various, often insectivorous, plants with leaves modified into a pitcher like receptacle or ascidium, often with a sticky liquid at the base in which insects are trapped, as in some species of… …  

  • pitcher plant — noun any of various insectivorous plants of the genera Sarracenia, Nepenthes, or Darlingtonia that have pitcher like leaves with slippery sides that attract and trap insects …   Wiktionary

  • pitcher plant — noun a plant with a deep fluid filled pouch in which insects are trapped and absorbed. [Many species, chiefly in the families Sarraceniaceae (New World) and Nepenthaceae (Old World).] …   English new terms dictionary

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