Fatty herbs

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Fatty herbs
Pinguicula ramosa

Pinguicula ramosa

Systematics
Nuclear eudicotyledons
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Water hose family (Lentibulariaceae)
Genre : Fatty herbs
Scientific name
Pinguicula
L.

The fatty herbs ( pinguicula ), also called fatty leaves in Liechtenstein and parts of German-speaking Switzerland , are a genus of carnivorous plants (carnivores) from the water hose family (Lentibulariaceae). About 102 species have been known since 2017, four of which are also native to German-speaking countries, but the majority are found in Central America .

description

Winter rosette of Pinguicula cyclosecta
Summer rosette of Pinguicula cyclosecta

Growth forms

Almost all butterwort species are perennial herbaceous plants (except for the annual species Pinguicula crenatiloba , Pinguicula sharpii , Pinguicula takakii and Pinguicula pumila ). All species form basal rosettes .

The fatty herbs can be roughly divided into two main groups, each with two subgroups. The subdivision of the main groups is based on climatic conditions, that of the subgroups on morphological features.

In general, it applies to all fatty herbs that they form so-called vegetative and generative rosettes that change with the season. Tropical growth forms end any rosette formation with the formation of a flower and after this, in turn, change into the next rosette form. The so-called “tempered growth forms”, on the other hand, form a vegetative rosette, but this does not bloom, but rather forms a hibernacle in its center , which serves as a wintering organ. After the formation of the hibernacle, the leaves of the vegetative rosette die off. Only after overwintering and new rosette shoots does the plant begin to form a flower.

The shape of the rosettes of a species serves as a distinguishing feature of the subgroups. If vegetative and generative rosettes of a species are identical in their appearance, then one speaks of "homophyllic growth", if they differ in shape and / or size, one speaks of "Heterophyllic growth".

This results in four shapes:

  • Tropical growth type : Species that do not experience cold periods and that alternately form rosettes and bloom.
    • Tropical-heterophyllous growth type : vegetative and generative rosette of a species differ in shape and / or size. Examples: Pinguicula cyclosecta , Pinguicula acuminata or Pinguicula moranensis .
    • Tropical-homophyllous growth type : vegetative and generative rosette of a species are identical in appearance. Examples: Pinguicula emarginata , Pinguicula filifolia or Pinguicula pumila .
  • Temperate growth habit : species of temperate zones with cold periods. They alternately form rosettes and alternately bloom and overwinter.
    • Temperate-heterophyllous growth habit type : vegetative and generative rosette of a species differ in shape and / or size. Examples: Pinguicula lutea or Pinguicula lusitanica .
    • Temperate homophyllous growth type : vegetative and generative rosette of a species are identical in appearance. Examples: Pinguicula alpina , Pinguicula grandiflora or Pinguicula vulgaris .

root

The roots of the fatty herbs are only weakly developed. It is white and fine and primarily serves to anchor in the ground, to absorb moisture and trace elements. In the case of species of temperate zones that develop hibernacles , these are rootless, with the exception of the Alpine butterwort . In the (few) epiphytic species (for example Pinguicula lignicola ) the roots are additionally provided with adhesive discs.

Pinguicula laxifolia on site

leaves

The leaves are smooth, firm and succulent , mostly light green, sometimes with a reddish tinge. They are - depending on the species - between 2 and 30 centimeters in size. In relation to the total size of the plant, the leaves are large and differently shaped depending on the clan; however, ovoid, spatulate or elongated shapes are often found.

Representation of the catching apparatus of the fatty herbs

Like all genera of the hose family , the fatty herbs are carnivorous. The leaf surface is provided with two types of glands for secretion : pedunculated glands and sessile glands. The secretion excreted by the stalked glands, to which prey animals stick, makes the leaves shine greasy. This shine probably attracts the prey - similar to other carnivores with sticky traps ( sundew , rainbow plants ). The captured animal then comes into contact with the sessile glands on the leaf surface, from which the digestive juice containing enzymes is excreted. Detected enzymes are amylase , esterase , phosphatase , protease and ribonuclease . The leaves are agile, but very slow, and can curl up at the edges over prey that is not in the center of the leaf. They can also form small depressions in the leaf surface around the prey, in which digestive juices collect for the purpose of better decomposition of the prey. Leaf areas that have already taken prey once cannot decompose prey again because the stalked glands are only "one-way" glands. The nutrients released by the decomposition of the prey are then absorbed through openings in the cuticle . Since the cuticle also protects the plants from drying out and this is often broken through the openings in the case of fatty herbs, the genus is dependent on humid habitats.

The range of prey mostly includes the smallest flying insects, but the plants can also efficiently utilize pollen , which is blown onto their relatively large leaf surface.

Pinguicula vulgaris , side view of the flower

blossoms

As with almost all carnivores, the hermaphrodite flowers protrude far beyond the actual plant to prevent possible pollinators from being caught. The solitary, long-blooming flowers, which most clearly show the relationship between the fatty herbs and the other water hose plants, are zygomorphic , the crown has two pronounced lips and is spurred at its base. The overgrown calyx is usually five-part, the upper lip three-part, the lower lip two-part. Most of the flowers are blue, purple or white, often with yellow, greenish or reddish colors are less common. The latter is particularly pronounced in the bright red flowers of Pinguicula laueana and Pingucula caryophyllacea .

The exact shape of the flower serves as a diagnostic feature to subdivide the genus into sub-genera, as well as the flower color and, in the case of multi-colored flowers, their combination.

Fruit and seeds

The egg-shaped to spherical capsule fruits open in two flaps when it is dry and close again when it is damp, in order to protect the numerous seeds and to promote their spread through wind scattering . With a length of 0.5 to 1 millimeter, relatively fine seeds are golden brown. The seeds of most species have a net pattern on their surface so that they can float on water surfaces without sinking (with the exception of epiphythic species, whose seed surface is smooth).

Sets of chromosomes

The basic chromosome numbers for Pinguicula species are usually x = 8 or x = 11, an exception to this rule is Pinguicula lusitanica , whose basic chromosome number is x = 6.

Vegetative propagation

In addition to generative propagation via seeds, there are several options for vegetative propagation in this genus . Many butterwort species (e.g. Pinguicula vulgaris ) form small bulbs at the time of flowering or shortly afterwards, from which new, genetically identical plants develop. A few species also form runners (e.g. Pinguicula calyptrata , Pinguicula vallisnerifolia ) or kindlings (e.g. Pinguicula heterophylla , Pinguicula primuliflora ) on their leaf tips.

distribution

The genus Pinguicula is distributed over the entire northern hemisphere of the earth; in Africa the distribution is restricted to the extreme northwest. Above all, however, the Pinguicula species can be found from Mexico via Central and Cuba to South America , where the occurrences radiate far across the equator to Tierra del Fuego . The genus Pinguicula is not represented only in Australia and New Zealand .

The area of ​​origin of the genus Pinguicula is probably Mexico, which is also the center of diversity of the genus - around 50 percent of the approximately 100 species are found in Mexico alone, twelve species are found in Europe and ten in North America. From Mexico, the forerunners of the genus Pinguicula probably spread to today's Europe before the earlier supercontinents drifted apart irreconcilably (compare also: Laurasia , Pangea ).

Far more than half of all species have very small areas . The two most widespread species, the common butterwort ( Pinguicula vulgaris ) and the Alpine butterwort ( Pinguicula alpina ), are also native to German-speaking countries. As an alpine plant, the thin-spurred butterwort ( Pinguicula leptoceras ) can also be found in Austria and Switzerland and the large-flowered butterwort ( Pinguicula grandiflora ) in Switzerland , an anointed location in North Rhine-Westphalia is also known for the latter .

Location requirements

Butterwort ( Pinguicula leptoceras )
on the Timmelsjoch in South Tyrol

In general, butterwort species do best in nutrient-poor, neutral to alkaline soils . However, different species have also conquered other soils such as acid peat ( Pinguicula vulgaris , Pinguicula calyptrata , Pinguicula lusitanica ) or pure gypsum ( Pinguicula gypsicola ) or sometimes settle on bare, upright rock ( Pinguicula ramosa , Pinguicula vallisneriifolia ). A few species have also turned into epiphytes ( Pinguicula casabitoana , Pinguicula lignicola ).

Fatty herbs need biotopes that are damp to wet at least during the growing season, but in the form of succulent winter rosettes can survive periods of relative to extremely severe drought. Spray or seepage water can be sufficient moisture. Unlike many other carnivores, fatty herbs prefer open, but not directly sunny locations, often even partially shaded to shady locations are preferred.

Danger

The endangerment of the Pinguicula species cannot be reduced to a common denominator, as the situation of the individual species is very different. They differ greatly in their distribution and have different location requirements. However, some endemics such as Pinguicula ramosa , Pinguicula casabitoana or Pinguicula fiorii are particularly threatened , with habitat destruction being the most threatening factor. The North American Pinguicula ionantha is listed in Appendix 1 of the Washington Convention on Endangered Species . The species occurring in Germany are all protected under the Federal Species Protection Ordinance.

Botanical history

Common butterwort ( Pinguicula vulgaris )
Illustration in:
Otto Wilhelm Thomé:
" Flora of Germany, Austria and Switzerland ",
Gera, 1885

The butterwort was mentioned for the first time as "zitroch chrawt or smalz chrawt" by Vitus Auslasser in his herbal book "Macer de Herbarium" from 1479 . The name "Zittrochkraut" is still in use today in Tyrol for the fatty herbs. The botanical name goes back to Conrad Gessner , who in 1561 referred to the shiny leaves in his "Horti Germaniae", "propter pinguia et tenera folia ..." (Latin pinguis = fat). The current name "Fettkraut" or rarely "Fettblatt" reflects this original name.

1583 differed Clusius in his "Historia stirpium rariorum per Pannoniam, Austriam" already two forms, a blue-flowered (= Pinguicula vulgaris ) and a white-flowered (= Pinguicula alpina ); In 1753 Linné added Pinguicula villosa and Pinguicula lusitanica to his "Species Plantarum" . The number of known species rose rapidly in the course of the 19th century, mainly due to new discoveries in the exploration of the new continents; In 1844 32 species were known.

When W. Marshall drew Charles Darwin's attention to the insects that stuck to the leaves in 1875 , he examined the plants more closely and determined the carnivory of the genus. In his groundbreaking monograph on the genus from 1966 , Siegfried Jost Casper distinguished only 46 species, a number that almost doubled in the following four decades. More species are still being discovered, especially in Mexico , but some species have only recently been described in Europe , so that over 80 species are now known.

An important step in further research into the genus was the establishment of the International Pinguicula Study Group (IPSG) in the 1990s, an organization made up of scientists and amateurs.

Systematics

Within the water hose family (Lentibulariaceae), the fatty herbs ( Pinguicula ) are considered to be the genus with the most original characteristics.

According to Siegfried Jost Casper 1966 , the genus Pinguicula is systematically divided into three sub-genera with 15 sections . A phylogenetic investigation of the genus (for more details see phylogenetics ) made the need for a revision of the genus system clear, but Casper's system is still in use.

Phylogenetics

A phylogenetic study by Cieslak et al. 2005 showed that all sub-genera and many of the species-rich sections (with a total of more than 60 percent of the species concerned) are polyphyletic or paraphyletic . In order to keep the cladogram clear, it is not shown here that is too detailed; Polyphyletic sections are marked with * in the following .





Clade I (sections Temnoceras * , Orcheosanthus * , Longitubus, Heterophyllum * , Agnata * , Isoloba * , Crassifolia)


   

Clade II (Section Micranthus * = Pinguicula alpina )



   

Klade III (sections Micranthus * , Nana)



   

Clade IV (Section Pinguicula)



   

Clade V (Isoloba * , Ampullipalatum, Cardiophyllum sections )


The systematic classification of the genus Pinguicula according to the classification of Ernst and von Casper were often artificial groups that had little to do with the natural relationship. In 2018, Andreas Fleischmann and Aymeric Roccia published a systematic breakdown of the genus Pinguicula , which corresponds to the phylogenetic relationships.

use

Fatty herbs are popular ornamental plants among lovers of carnivores; Especially species from temperate areas and more easily cultivable Mexican species can often be found in corresponding collections. The most widespread are the two hybrids Pinguicula × 'Sethos' and Pinguicula × 'Weser'. Both are crosses of Pinguicula ehlersiae with Pinguicula moranensis , which are also used by commercial orchid breeders for pest control.

literature

  • S. Jost Casper : Monograph of the genus Pinguicula L. (= Bibliotheca Botanica. H. 127/128, ISSN  0067-7892 ). Swiss beard, Stuttgart 1966.
  • Laurent Legendre: The genus Pinguicula L. (Lentibulariaceae): an overview. In: Acta Botanica Gallica. Volume 147, No. 1, 2000, ISSN  1253-8078 , pp. 77-95, doi : 10.1080 / 12538078.2000.10515837 .
  • Kai Müller, Thomas Borsch, Laurent Legendre, Stefan Porembski, Inge Theisen, Wilhelm Barthlott : Evolution of Carnivory in Lentibulariaceae and the Lamiales. In: Plant Biology. Volume 6, No. 4, 2004, ISSN  0894-4563 , pp. 477-490, doi : 10.1055 / s-2004-817909 .
  • Wilhelm Barthlott, Stefan Porembski, Rüdiger Seine, Inge Theisen: Carnivores. Biology and culture of carnivorous plants. Eugen Ulmer GmbH & Co., Stuttgart 2004, ISBN 3-8001-4144-2 .

Individual evidence

  1. a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz ca cb cc cd ce cf cg ch ci cj ck cl cm cn co cp cq cr cs ct cu cv cw cx cy cz da db dc dd de df Rafaël Govaerts (Ed.): Pinguicula. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved December 19, 2018.
  2. Thomas Cieslak, Jai Santosh Polepalli, Adam White, Kai Müller, Thomas Borsch, Wilhelm Barthlott, Juerg Steiger, Adam Marchant, Laurent Legendre: Phylogenetic analysis of Pinguicula (Lentibulariaceae): chloroplast DNA sequences and morphology support several geographically distinct radiations. In: American Journal of Botany. , Volume 92, Issue 10, Columbus Ohio, 2005, pp. 1723-1736. ISSN  0002-9122 doi : 10.3732 / ajb.92.10.1723 PDF.
  3. ^ Andreas Fleischmann, Aymeric Roccia: Systematics and evolution of Lentibulariaceae: I. Pinguicula. , Pp. 70-80. In: AM Ellison, L. Adamec (Eds.): Carnivorous plants: physiology, ecology, and evolution. Oxford University Press, 2018. doi : 10.1093 / oso / 9780198779841.003.0006

Web links

Commons : Butterworts ( Pinguicula )  - album with pictures, videos and audio files
This article was added to the list of excellent articles on February 4, 2006 in this version .