Pinguicula 871179 223643781 2008-07-05T01:27:28Z Lightbot 7178666 Units/dates/other {{Taxobox | name = Butterwort | image = Pinguicula_ne1.JPG | image_width = 250px | image_caption = Butterwort with prey (''[[Pinguicula gigantea]]'') | regnum = [[Plant]]ae | divisio = [[Flowering plant|Magnoliophyta]] | classis = [[Magnoliopsida]] | ordo = [[Lamiales]] | familia = [[Lentibulariaceae]] | genus = '''''Pinguicula''''' | genus_authority = [[Carolus Linnaeus|L.]] | subdivision_ranks = Species | subdivision = About 80, see [[List of Pinguicula species|separate list]]. }} The '''butterworts''' are a group of [[carnivorous plant]]s comprising the [[genus]] '''''Pinguicula'''''. Members of this genus use sticky, [[glandular]] leaves to lure, trap, and digest [[insects]] in order to supplement the poor mineral nutrition they obtain from the environments. Of the roughly 80 currently known [[species]], 12 are native to [[Europe]], 9 to [[North America]], and the rest are found in northern [[Asia]], [[South America|South]] and [[Central America]] and southern [[Mexico]]. The name ''Pinguicula'' is derived from a term coined by [[Conrad Gesner]], who in his 1561 work entitled ''Horti Germaniae'' commented on the glistening leaves: ''"propter '''pinguia''' et tenera folia…"'' (lat. pinguis = fat). The common name "butterwort" reflects this characteristic. == Characteristics == The majority of ''Pinguicula'' are [[perennial plant]]s. The only known [[annual plant|annuals]] are [[Pinguicula sharpii|''P. sharpii'']], [[Pinguicula takakii|''P. takakii'']], [[Pinguicula crenatiloba|''P. crenatiloba'']], and [[Pinguicula pumila|''P. pumila'']]. All species form stemless [[Rosette (botany)|rosettes]]. === Habit === [[Image:PinguiculaCyclosectaWinter.jpg|thumb|180px|right|Winter rosette of ''Pinguicula cyclosecta'' (non-carnivorous)]] [[Image:Pinguicula cyclosecta summer.jpg|thumb|180px|right|Summer rosette of ''Pinguicula cyclosecta'' (carnivorous)]] Butterworts can be divided roughly into two main groups based on the [[climate]] in which they grow; each group is the further subdivided based on [[Morphology (biology)|morphological]] characteristics. Although these groups are not [[cladistics|cladistically]] supported by genetic studies,<ref name="cieslak2005">{{cite journal | author=Cieslak T, Polepalli JS, White A, Müller K, Borsch T, Barthlott W, Steiger J, Marchant A, Legendre L | title=Phylogenetic analysis of ''Pinguicula'' (Lentibulariaceae): chloroplast DNA sequences and morphology support several geographically distinct radiations | journal=[[American Journal of Botany]] | volume=92| year=2005| pages=1723–1736 | doi= 10.3732/ajb.92.10.1723}}</ref> these groupings are nonetheless convenient for horticultural purposes. [[Tropical]] butterworts either form somewhat compact winter rosettes composed of fleshy leaves or retain carnivorous leaves year-round. [[Temperate]] species often form tight buds (called [[Hibernaculum|hibernacula]]) composed of scale-like leaves during a winter [[dormancy]] period. During this time the roots (with the exception of [[Pinguicula alpina|''P. alpina'']]) and carnivorous leaves wither.<ref name="legendre2000">{{cite journal | author=Legendre L | title=The genus ''Pinguicula'' L. (Lentibulariaceae): an overview | journal=Acta Botanica Gallica | volume=141 | issue=1 | year=2002 | pages=77–95 | url=http://www.pinguicula.org/pages/culture/Overview.htm}}</ref> Temperate species flower when they form their summer rosettes while tropical species flower at each rosette change. Many butterworts cycle between rosettes composed of carnivorous and non-carnivorous leaves as the seasons change, so these two ecological groupings can be further divided according to their ability to produce different leaves during their growing season. If the growth in the summer is different in size or shape to that in the early spring (for temperate species) or in the winter (tropical species), then plants are considered [[heterophyllous]]; whereas uniform growth identifies a [[homophyllous]] species. This results in four groupings: *'''Tropical butterworts''': species which do not undergo a winter dormancy but continue to alternately bloom and form rosettes. **'''''Heterophyllous tropical species''''': species that alternate between rosettes of carnivorous leaves during the warm season and compact rosettes of fleshy non-carnivorous leaves during the cool season. Examples include [[Pinguicula moranensis|''P. moranensis'']], [[Pinguicula gypsicola|''P. gypsicola'']], and [[Pinguicula laxifolia|''P. laxifolia'']]. **'''''Homophyllous tropical species''''': these species produce rosettes of carnivorous leaves of roughly uniform size throughout the year, such as [[Pinguicula gigantea|''P. gigantea'']]. *'''Temperate butterworts''': these plants are native to climate zones with cold winters. They produce a winter-resting bud ([[Hibernaculum|hibernacula]]) during the winter. **'''''Heterophyllous temperate species''''': species where the vegetative and generative rosettes differ in shape and/or size, as seen in [[Pinguicula lutea|''P. lutea'']] and [[Pinguicula lusitanica|''P. lusitanica'']]. **'''''Homophyllous temperate species''''': the vegetative and generative rosettes appear identical, as exhibited by [[Pinguicula alpina|''P. alpina'']], [[Pinguicula grandiflora|''P. grandiflora'']], and [[Pinguicula vulgaris|''P. vulgaris'']]. === Roots === The [[root|root system]] of ''Pinguicula'' species is relatively undeveloped. The thin, white roots serve mainly as an [[anchor]] for the plant and to absorb moisture (nutrients are absorbed through carnivory). In temperate species these roots wither (except in [[Pinguicula alpina|''P. alpina'']]) when the [[hibernaculum]] is formed. In the few [[epiphytic]] species (such as [[Pinguicula lignicola|''P. lignicola'']]), the roots form anchoring suction cups. === Leaves and carnivory === [[Image:Pinguicula and prey ne.JPG|thumb|210px|left|A fly trapped on a butterwort leaf.]] The [[leaf]] [[blade]] of a butterwort is smooth, rigid, and [[succulent]], usually bright green or pinkish in colour. Depending on species, the leaves are between 2 and 30 [[centimeter|cm.]](1-12") long. The leaf shape depends on the species, but is usually roughly [[Leaf#Leaf terminology|obovate]], [[Leaf#Leaf terminology|spatulate]], or [[Leaf#Leaf terminology|linear]]. [[Image:Pinguicula vector en.svg|right|250px|Vector graphic of the trapping and digestive features of a ''Pinguicula'' leaf]] Like all members of the family [[Lentibulariaceae]], butterworts are [[carnivorous]]. In order to catch and digest insects, the leaf of a butterwort uses two specialized glands which are scattered across the leaf surface (usually only on the upper surface, with the exception of [[Pinguicula gigantea|''P. gigantea'']] and ''[[Pinguicula longifolia|P. longifolia ssp. longifolia]]''). One is termed a ''peduncular gland'', and consists of a few [[secrete|secretory]] cells on top of a single stalk cell. These cells produce a [[mucilage]]nous secretion which forms visible [[droplet]]s across the leaf surface. This wet appearance probably helps lure prey in search of water (a similar phenomena is observed in the [[Drosera|sundews]]). The droplets secrete only limited enzymes and serve mainly to entrap insects. On contact with an insect, the peduncular glands release additional mucilage from special [[Reservoir (water)|reservoir]] cells located at the base of their stalks.<ref name="legendre2000" /> The insect will begin to struggle, triggering more glands and encasing itself in mucilage. Some species can bend their leaf edges slightly by [[thigmotropism]], bringing additional glands into contact with the trapped insect. The second type of gland found on butterwort leaves are ''sessile glands'' which lie flat on the leaf surface. Once the prey is entraped by the peduncular glands and digestion begins, the initial flow of [[nitrogen]] triggers enzyme release by the sessile glands.<ref name="legendre2000" /> These enzymes, which include [[amylase]], [[esterase]], [[phosphatase]], [[protease]], and [[ribonuclease]] break down the digestible components of the insect body. These fluids are then absorbed back into the leaf surface through [[Plant cuticle|cuticular]] holes, leaving only the [[chitin]] [[exoskeleton]] of the larger insects on the leaf surface. The holes in the cuticle which allow for this digestive mechanism also pose a challenge for the plant, since they serve as breaks in the [[Plant cuticle|cuticle]] (waxy layer) that protects the plant from [[desiccation]]. As a result, most butterworts live in humid environments. [[Image:Pinguicula vulgaris 140505a.jpg|thumb|180px|right|Flower of ''P. vulgaris'']] Butterworts are usually only able to trap small insects and those with large wing surfaces. They can also digest [[pollen]] which lands on their leaf surface. The secretory system can only function a single time, so that a particular area of the leaf surface can only be used to digest insects once.<ref name="legendre2000" /> === Flowers === [[Image:Pinguicula hybrid ne.JPG|thumb|180px|right|The flower of a hybrid butterwort]] As with almost all [[carnivorous plants]], the flowers of butterworts are held far above the rest of the plant by a long stalk, in order to reduce the probability of trapping potential pollinators. The single, long-lasting flowers are [[zygomorphic]], with two lower lip petals characteristic of the [[Lentibulariaceae|bladderwort family]], and a spur extending from the back of the flower. The [[sepals| calyx]] has five sepals, and the [[petal]]s are arranged in a two-part lower lip and a three-part upper lip. Most butterwort flowers are blue, violet or white, often suffused with a yellow, greenish or reddish tint. ''[[Pinguicula laueana|P. laueana]]'' and the newly described [[Pinguicula caryophyllacea|''P. caryophyllacea'']] are unique in having a strikingly red flowers. Butterworts are often cultivated and hybridized primarily for their flowers. The shape and colors of butterwort flowers are distinguishing characteristics which are used to divide the genus into subgenera and to distinguish individual species from one another. === Fruit and seed === The round to egg-shaped [[Capsule (fruit)|seed capsules]] open when dry into two halves, exposing numerous small (0.5-1 mm), brown [[seeds]]. If moisture is present the [[silique]] closes, protecting the seed and opening again upon dryness to allow for [[seed dispersal#Wind|wind dispersal]]. Many species have a net-like pattern on their seed surface to allow them to land on water surfaces without sinking, since many non-epiphytic butterworts grow near water sources. The [[haploid]] [[chromosome]] number of butterworts is either n = 8 or n = 11 (or a multiple thereof), depending on species. The exception is ''[[Pinguicula lusitanica|P. lusitanica]]'', whose chromosome count is n = 6.{{Fact|date=February 2007}} === Vegetative propagation === As well as [[sexual reproduction]] by [[seed]], many butterworts can reproduce [[asexual]]ly by [[vegetative reproduction]]. Many members of the genus form offshoots during or shortly after flowering (''e.g.'' ''[[Pinguicula vulgaris|P. vulgaris]]''), which grow into new [[Cloning|genetically identical]] adults. A few other species form new [[Offshoot (plant)|offshoots]] using [[stolons]] (''e.g.'' ''[[Pinguicula calyptrata|P. calyptrata]]'', ''[[Pinguicula vallisnerifolia|P. vallisnerifolia]]'') or form plantlets at the leaf margins (''e.g.'' ''[[Pinguicula heterophylla|P. heterophylla]]'', ''[[Pinguicula primuliflora|P. primuliflora]]''). == Distribution == [[Image:Pinguicula distribution.svg|thumb|240px|right|''Pinguicula'' distribution]] Butterworts are distributed throughout the [[northern hemisphere]] ([http://www.pinguicula.org/pages/culture/Overview_fichiers/image002.jpg map]). The greatest concentration of species, however, is in humid mountainous regions of [[Central America]] (including [[Mexico]]) and [[South America]], where populations can be found as far south [[Tierra del Fuego]]. [[Australia]] is the only [[continent]] without any native butterworts. Butterworts probably originated from modern day Central America, which is also the center of ''Pinguicula'' diversity; roughly 50% of butterwort species are found here. From there, the genus likely spread to Europe, before [[continental drift]] split the continents apart. The great majority of ''Pinguicula'' species have a very limited [[distribution]]. The two butterwort species with the widest distribution - ''[[Pinguicula alpina|P. alpina]]'' and ''[[Pinguicula vulgaris|P. vulgaris]]'' - are found throughout much of Europe and North America. Other species found in the [[United States]] include ''[[Pinguicula caerulea|P. caerulea]]'', ''[[Pinguicula ionantha|P.ionantha]]'', ''[[Pinguicula lutea|P. lutea]]'', ''[[Pinguicula macroceras|P. macroceras]]'', ''[[Pinguicula planifolia|P. planifolia]]'', ''[[Pinguicula primuliflora|P. primuliflora]]'', ''[[Pinguicula pumila|P. pumila]]'', and ''[[Pinguicula villosa|P. villosa]]''. == Habitat == [[Image:Pinguicula macroceras nortensis ne1.JPG|thumb|165px|left|''P. macroceras ssp. nortensis'' growing on a wet rock wall in northern California.]] [[Image:Pinguicula leptoceras.jpg|thumb|200px|right|''P. leptoceras'' in alpine grassland in Südtirol, Italy]] In general, butterworts grow in nutrient poor, alkaline soils. Some species have adapted to other soil types, such as acidic [[peat bog]]s (ex. ''[[Pinguicula vulgaris|P. vulgaris]]'', ''[[Pinguicula calyptrata|P. calyptrata]]'', ''[[Pinguicula lusitanica|P. lusitanica]]''), soils composed of pure [[gypsum]] (''[[Pinguicula gypsicola|P. gypsicola]]'' and other Mexican species), or even vertical rock walls (''[[Pinguicula ramosa|P. ramosa]]'', ''[[Pinguicula vallisnerifolia|P. vallisnerifolia]]'', and most of the Mexican species). A few species are epiphytes (''[[Pinguicula casabitoana|P. casabitoana]]'',''[[P. hemiepiphytica]]'', ''[[Pinguicula lignicola|P. lignicola]]''). Many of the Mexican species commonly grow on mossy banks, rock, and roadsides in oak-pine forests. ''Pinguicula macroceras ssp. nortensis'' has even been observed growing on hanging dead grasses. Each of these environments is relatively nutrient poor, allowing butterworts to compete for space. Butterworts need habitats that are almost constantly moist or wet, at least during their carnivorous growth stage. Many Mexican species lose their carnivorous leaves, and sprout succulent leaves, or die back to onion-like "bulbs" to survive the winter drought, at which point they can survive in bone dry conditions. This moisture can be supplied by either a high [[water table|groundwater table]], or by high humidity or precipitation. Unlike many other carnivorous plants that require sunny locations, many butterworts thrive in part-sun or even shady conditions. == Environmental status == The environmental threats faced by various ''Pinguicula'' species depend on their location and on how widespread their distribution is. Most greatly endangered are the species which are [[endemic (ecology)|endemic]] to small areas, such as ''[[Pinguicula ramosa|P. ramosa]]'', ''[[Pinguicula casabitoana|P. casabitoana]]'', and ''[[Pinguicula fiorii|P. fiorii]]''. These populations are threatened primarily by [[habitat destruction]]. [[Wetland]] destruction has threatened several US species. Most of these are federally listed as either threatened or endangered, and ''[[Pinguicula ionantha|P. ionantha]]'' is listed on [[CITES]] appendix I, giving it additional protection. == Botanical history == [[Image:Illustration Pinguicula vulgaris0.jpg|thumb|180px|''Pinguicula vulgaris'', illustration]] The first mention of butterworts in botanical literature is an entry entitled ''Zitroch chrawt oder smalz chrawt'' (trans: "''zitroch''" herb or lard herb) by [[Vitus Auslasser]] in his 1479 work on medicinal herbs entitled ''Macer de Herbarium''. The name "''Zittrochkraut''" is still used for butterworts in [[Tirol]], Austria. In 1583, [[Clusius]] already distinguished between two forms in his ''Historia stirpium rariorum per Pannoniam, Austriam'': a blue-flowered form (''[[Pinguicula vulgaris|P. vulgaris]]'') and a white-flowered form (''[[Pinguicula alpina]]''). [[Carolus Linnaeus|Linnaeus]] added ''[[Pinguicula villosa|P. villosa]]'' and ''[[Pinguicula lusitanica|P. lusitanica]]'' when he published his ''[[Species Plantarum]]'' in 1753. The number of known species rose sharply with the exploration of the new continents in the 19th century; in 1844, 32 species were known. It was only in the late 19th century that the carnivory of this genus began to be studied in detail. In a letter to [[Asa Gray]] dated June 3rd 1874, [[Charles Darwin]] mentioned his early observations of the butterwort's digestive process and [[insectivorous]] nature. (See Gray Herbarium of Harvard University (103).) Darwin studied these plants extensively.<ref>{{cite book | author=[[Charles Darwin|Darwin]] C | title=Insectivorous plants | publisher=John Murray | location=London | year=1875 | url=http://pages.britishlibrary.net/charles.darwin3/insectivorous/insect01.htm }}</ref> [[Siegfried Jost Casper|S. J. Casper's]] large 1966 monograph of the genus<ref name="casper1966">{{cite book | author=Casper SJ | title=''Monographie der Gattung ''Pinguicula'' L. (Heft 127/128, Vol 31) | publisher=[[Bibliotheca Botanica]] | location=Stuttgart| year=1966 }}</ref> included 46 species, a number which has almost doubled since then. Many exciting discoveries have been made in recent years, especially in [[Mexico]]. Another important development in the history of butterworts is the formation of the [[International Pinguicula Study Group]], an organization dedicated to furthering the knowledge of this genus and promoting its popularity in cultivation, in the 1990s. == Uses == Butterworts are widely cultivated by carnivorous plant enthusiasts. The temperate species and many of the Mexican butterworts are relatively easy to grow and have therefore gained relative popularity. Two of the most widely grown plants are the hybrid [[cultivar]]s ''Pinguicula'' × 'Sethos' and ''Pinguicula'' × 'Weser'. Both are crosses of ''[[Pinguicula ehlersiae]]'' and ''[[Pinguicula moranensis]]'', and are employed by commercial [[orchid]] nurseries to combat pests. Butterworts also produce a strong bactericide which prevents insects from rotting while they are being digested. According to [[Carolus Linnaeus|Linnaeus]], this property has long been known by northern Europeans, who applied butterwort leaves to the [[sore]]s of [[cattle]] to promote healing.<ref>{{cite book | author=D'Amato P | title=The savage garden: cultivating carnivorous plants | publisher=Ten Speed Press | year=1988 | isbn= ISBN 0-89815-915-6 }}</ref> Additionally, butterwort leaves were used to [[curdle]] milk and form a buttermilk-like [[fermented milk product]] called [[filmjölk]]. == Classification == :''For a list of species, see the separate article [[List of Pinguicula species]].'' ''Pinguicula'' belong to the Bladderwort family ([[Lentibulariaceae]]), along with [[Utricularia|''Utricularia'']] and [[Genlisea|''Genlisea'']]. [[Siegfried Jost Casper]] [[systematics|systematically]] divided them into three [[subgenus|subgenera]] with 15 [[Section (botany)|sections]].<ref name="casper1966" /> A detailed study of the phylogenetics of butterworts by Cieslak ''et al.'' (2005)<ref name="cieslak2005" /> found that all of the currently accepted [[subgenus|subgenera]] and many of the [[section (biology)|sections]] were [[polyphyletic]]. The diagram below gives a more accurate representation of the correct [[cladogram]]. Polyphyletic sections are marked with an '''<nowiki>*</nowiki>'''. ┌────Clade I (Sections Temnoceras '''<nowiki>*</nowiki>''', Orcheosanthus '''<nowiki>*</nowiki>''', Longitubus, │ Heterophyllum '''<nowiki>*</nowiki>''', Agnata '''<nowiki>*</nowiki>''', Isoloba '''<nowiki>*</nowiki>''', Crassifolia) │ ┌───┤ │ │ │ │ ┌──────┤ └────Clade II (Section Micranthus '''<nowiki>*</nowiki>''' = ''P. alpina'') │ │ │ │ ┌───┤ └────────Clade III (Sections Micranthus '''<nowiki>*</nowiki>''', Nana) │ │ │ │ ───┤ └───────────────Clade IV (Section Pinguicula) │ │ └───────────────────Clade V (Sections Isoloba '''<nowiki>*</nowiki>''', Ampullipalatum, Cardiophyllum) == References == Much of the content of this article comes from [http://de.wikipedia.org/wiki/Fettkräuter the equivalent German-language wikipedia article] (retrieved [[March 29]], 2006). <!--See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for an explanation of how to generate footnotes using the <ref(erences/)> tags--> <references/> ==Further reading== * {{cite book | author=Barthlott W, Porembski S, Seine R, Theisen I | title=Karnivoren | publisher=Verlag Eugen Ulmer | location=Stuttgart| year=2004 | isbn= ISBN 3-8001-4144-2 }} * {{cite journal | author=Müller K, Borsch T, Legendre L, Porembski S, Theisen I, Barthlott W | title=Evolution of carnivory in Lamiales | journal=Plant Biology | volume=6| year=2004| pages=1–14 | doi=10.1055/s-2004-817909}} ==External links== {{Commons|Pinguicula}} {{wikispecies|Pinguicula}} * [http://www.pinguicula.org/ An exhaustive website on the genus ''Pinguicula''] * Schlauer, J. [http://www.omnisterra.com/bot/cp_home.cgi Carnivorous Plant Database], version 15 November 16: 25. * [http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Pinguicula&SPECIES_XREF=&TAXON_NAME_XREF=&RANK=species Flora Europaea: ''Pinguicula'' species list] * [http://www.botany.org/Carnivorous_Plants/Pinguicula.php Botanical Society of America, ''Pinguicula'' - the Butterworts] {{CarnivorousPlants}} [[Category:Carnivorous plants of Africa]] [[Category:Carnivorous plants of Asia]] [[Category:Carnivorous plants of Central America]] [[Category:Carnivorous plants of Europe]] [[Category:Carnivorous plants of North America]] [[Category:Carnivorous plants of South America]] [[Category:Pinguicula]] {{Link FA|de}} [[ca:Pinguicula]] [[cs:Tučnice]] [[de:Fettkräuter]] [[es:Pinguicula]] [[fr:Grassette]] [[it:Pinguicula]] [[he:חמאית]] [[lt:Tuklė]] [[hu:Hízóka]] [[no:Tettegras]] [[pl:Tłustosz]] [[pt:Pinguicula]] [[ru:Жирянка]] [[fi:Yökönlehdet]] [[sv:Tätörter]]