Pitcher plant

Source: Wikipedia, the free encyclopedia.
Pitcher of Nepenthes distillatoria. A: Honey-gland from attractive surface of lid. B: Digestive fluid from interior of pitcher, in pocket-like depression of epidermis, opening downwards. C: Transverse section of the same.
Scanning electron micrograph
of a pitcher's inner surface
Pitcher plants growing in a bog in Pennsylvania

Pitcher plants are several different carnivorous plants that have modified leaves known as pitfall traps—a prey-trapping mechanism featuring a deep cavity filled with digestive liquid. The traps of what are considered to be "true" pitcher plants are formed by specialized leaves. The plants attract and drown their prey with nectar.[1]

Types

The term "pitcher plant" generally refers to members of the

Nepenthaceae and Sarraceniaceae are the most species-rich families of pitcher plants.[citation needed
]

Nepenthaceae

The Nepenthaceae contains a single

midrib of an otherwise unexceptional leaf. Old World pitcher plants are typically characterized as having reduced and symmetrical pitchers with a comprehensive waxy coating on the surface of the inner pitcher wall. 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.[citation needed
]

Sarraceniaceae

The New World pitcher plants (Sarraceniaceae), which comprise three genera, are ground-dwelling herbs whose pitchers arise from a horizontal

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 hybridize, making their classification a complex matter.[citation needed
]

The purple pitcher plant,

floral emblem of the province of Newfoundland and Labrador
, Canada.

Cephalotaceae

The

Cephalotaceae is a monotypic family with but one genus and species, Cephalotus follicularis. This species has a small (2–5 cm) pitcher similar in form to those of Nepenthes. Unlike in Nepenthes, in Cephalotus follicularis the petiole is attached to the rear of the upper trap rim rather than to the base of the pitcher.[2] The species occurs in only one location in southwestern Australia.[citation needed
]

Bromeliaceae

A few species of bromeliads (Bromeliaceae), such as Brocchinia reducta and Catopsis berteroniana, are known or suspected to be carnivorous.[3]

Feeding behavior

Attraction

Foraging, flying, or crawling insects such as flies are attracted to a cavity formed by the cupped leaf, often by visual lures such as anthocyanin pigments, and nectar. Many pitcher plants exhibit patterns of ultraviolet coloration which may play a role in attracting insects.[2] Some species, such as Cephalotus follicularis, likely use camouflage to trap insects, as their coloration matches that of the surrounding environment and the plants are often embedded in the substrate such that the traps are flush with the ground.[2]

Olfactory cues can also play a role in attraction. For example, Nepenthes rafflesiana uses flower-scent mimicry to attract insects to its pitchers.[4]

Capture

The rim of the pitcher (peristome) is slippery when moistened by condensation or nectar, causing insects to fall into the trap. The walls of the pitfall may be covered with waxy scales, protruding

excreta the plant absorbs.[6]

Digestion

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, pitcher plants all grow in locations where the soil is too poor in minerals and/or too acidic for most plants to survive. Pitcher plants supplement available nutrients and minerals (which plants normally obtain through their roots) with the constituents of their insect prey.[citation needed]

Feces-trapping symbiosis

Mature plants of

Tupaia montana), which feed on nectar that the plant produces but also defecate into the pitcher, providing nitrates and other nutrients. The plant and tree shrew have a symbiotic relationship. The rim of N. lowii is not slippery so that tree shrews can easily get in and out; it provides more nectar than other pitcher plants. The shape of the pitcher rim and the position of the nectar ensure that the animal's hindquarters are over the rim while it feeds.[7]

Nepenthes rafflesiana var. elongata has a similar relationship with Hardwicke's woolly bats (Kerivoula hardwickii).[8] The bats roost inside the pitchers and the plants derive much of their foliar nitrogen from the feces of the bats. Compared to other varieties of Nepenthes rafflesiana that do not exhibit this form of mutualism, N. rafflesiana var. elongata has elongated pitchers that can accommodate both single bats and mother-juvenile pairs. As well as its elongated shape, N. rafflesiana var. elongata has reduced volumes of pitcher fluid compared to other species, leaving more space to accommodate the bats.

Evolution of the form

It is widely assumed pitfall traps evolved by epiascidiation (infolding of the leaf with the adaxial or upper surface becoming the inside of the pitcher),

monocot lineage, representing a case of convergent evolution.[9] Some pitcher plant families (such as Nepenthaceae) are placed within clades consisting mostly of flypaper traps, indicating that some pitchers may have evolved from the common ancestors of today's flypaper traps by loss of mucilage.[11]

See also

References

  1. ^
    PMID 21937485
    .
  2. ^
    OCLC 71189676
    .
  3. S2CID 84947503
    .
  4. S2CID 82299236
    .
  5. PMID 25672361
    .
  6. doi:10.1071/IT96018
    .
  7. ^ Pitcher Plant Doubles as Toilet
  8. PMID 21270023
    .
  9. ^
    PMID 1523408
    .
  10. PMID 10523280
    .
  11. ^ Pritchard; et al. (2002). "Evolutionary adaptations in pitcher plants". International Journal of Evolutionary Biology. 12 (3): 62–81.

Further reading

External links

Wikimedia Commons has media related to Pitcher (plant).
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