Trap traps

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Trap traps
Genlisea violacea

Genlisea violacea

Systematics
Nuclear eudicotyledons
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Water hose family (Lentibulariaceae)
Genre : Trap traps
Scientific name
Genlisea
A.St.-Hil.

The trap traps ( Genlisea ) are a genus of plants in the water hose family (Lentibulariaceae). The approximately 29 species are carnivorous plants and are common in the New World and in Africa and Madagascar .

description

Rhizophyll from Genlisea violacea
Flower of Genlisea subglabra
Capsule fruit of Genlisea repens

Overall, the species of the genus Genlisea differ only slightly from one another.

Appearance

Fish trap species are rootless, rosette-shaped, annual or perennial herbaceous plants . With a diameter of 1 to 5 centimeters and heights of only a few centimeters, they are relatively small. The majority of the species forms runners .

leaves

A distinction is made between two types of leaf , namely the above-ground leaves and the underground traps, the fish trap leaves ("rhizophylls").

The above-ground leaves are in a rosette, light green and 3 to 50 millimeters long. They are mostly spatulate, occasionally spatulate-wrong-egg-shaped; their surface is smooth and without any visible veins. In some species, such as Genlisea aurea , the leaves are covered with a slimy secretion whose function is still unclear.

Falling

The traps are actually underground leaves, so-called rhizophylls, i.e. leaves emanating from a rhizome . The plants likely lure their prey through chemical attractants given off by the rhizophylls. The prey is ciliates , roundworms and other small ground dwellers. However, species with larger bladders also prey on vortex worms and little bristles .

The rhizophylls have the shape of an upturned Y, with the two arms twisted like a corkscrew; Slit-shaped openings are distributed along the "thread". Before that, however, the stalk thickens after several millimeters into a bladder, which has the function of a digestive organ. Between the threads and the bladder above, the rhizophyll is hollow and divided into chambers, which are separated from one another by directed hairs. The directed hairs only allow the prey to move in the direction of the bladder once it has penetrated through the opening, hence the German name "trap trap". In the bladder and in the rest of the trap, there are glands that digest the prey. It is unclear why the dissolved nutrients don't seep back out of the trap; among other things, weak negative pressures were assumed, which would make the traps act like pumps.

The carnivory of the genus Genlisea , already suspected by Charles Darwin , was not definitively proven until 1998.

Inflorescences and flowers

As with all carnivores, the inflorescence shafts protrude far beyond the plant itself with a height of up to 50 centimeters . At their end they have grape-shaped inflorescences with up to four flowers.

The hermaphrodite flowers are zygomorphic . The flowers are mostly purple or (in some American species) yellow and spurred .

Fruits and seeds

The fruits are small round capsule fruits . The way in which the fruits open to release the seeds, the dehiscence , serves as a distinguishing feature of the two subgenus (see below ): The capsule fruits of species of the subgenus Tayloria open along elongated slits, whereas the capsule fruits of the subgenus Genlisea stand out the tip of the capsule fruit at the end of a spiral incision. There are a few small seeds in the fruits. The seeds can only germinate for a short time.

distribution

Genlisea species thrive in the tropics . Their distribution areas are evenly Africa and Madagascar on the one hand and Central and South America on the other . The subgenus Tayloria (see below ) is limited in its occurrence to eastern Brazil . Neither species occurs on either continent. Unlike previously assumed, this evolutionary separation is not due to the drifting apart of the continents that used to belong together ( Gondwana theory ), but to the subsequent movement of an ancestral form from Africa to South America.

Traps ( Genlisea ), distribution map

Africa

Ten species are native to Africa; the main occurrence is found in the area of Zambia , Zimbabwe , Mozambique and Malawi , from where it radiates to Angola and Madagascar . Other small areas of distribution exist along the central African coast and in the extreme west of Africa ( Guinea , Sierra Leone , Guinea-Bissau , Ivory Coast ). The bypassing of the countries of Central Africa ( Democratic Republic of the Congo , Rwanda , Burundi ), which are mainly dominated by tropical rainforests , is interesting .

America

The center of the occurrence in the Neotropic is the northeast of South America , here especially Brazil . Of the eleven American species, nine are found there, four of which are endemic . Seven species are native to neighboring Venezuela , two are endemic. Minor occurrences can be found in Guyana , Colombia , Bolivia and Paraguay , to the north the genus extends over Central America ( Honduras ) to the islands of Trinidad and Cuba .

Site conditions

All species mainly colonize extreme, nutrient-poor and humus-poor, moist to wet locations, especially on Inselbergs and Ferricretes (iron crust soils), in which they often occur together with other carnivores (especially water hoses and sundew ), but also representatives of the Eriocaulaceae , Xyridaceae and Burmanniaceae . In addition, trap traps are occasionally found in white sand savannahs or swamps , a few semi-aquatic species such as Genlisea repens prefer water margins as a habitat.

Since the Inselberg areas, which are home to most of the species, are rare habitats, the species are rare, but are not to be regarded as threatened.

Systematics

The genus Genlisea was in 1883 by Auguste Saint-Hilaire in le Voyage dans District of Diamans , 2, page 428 installed . The botanical genus name Genlisea honors the French writer Félicité de Genlis (Stéphanie Félicité du Crest de Saint-Aubin, Comtesse de Genlis, Marquise de Sillery) (1746-1830).

Subgenera and species

The genus Genlisea includes about 29 species. According to Fleischmann 2012, it is divided into two sub-genres: Tayloria and Genlisea . The latter is in turn divided into three sections as follows: Here is the list of species and their distribution according to WCSP :

Foliage leaves Genlisea violacea

Phylogenetics

A study of the Lentibulariaceae family (Müller 2004) considered six species and resulted in the following preliminary cladogram:





African group 3 ( Genlisea hispidula )


   

African group 2 ( Genlisea stapfii )



   

African group 1 ( Genlisea margaretae )


   

South American species of the subgenus Genlisea




   

Subgenus Tayloria



The closest relatives of the trap traps are the water hoses .

genetics

With 63.4 Mbp for Genlisea margaretae and 63.6 Mbp for Genlisea aurea , the genus contains the two species with the smallest known genomes of all flowering plants . Also noteworthy is the size of the individual chromosomes , which, at 2.1 Mbp for Genlisea aurea, are in the range of bacteria .

use

From the early 1990s , the first species were sporadically cultivated by carnivore enthusiasts. Similar to their relatives, the water hoses, they usually lead a shadowy existence in the corresponding collections. Otherwise the genus is not used by humans.

literature

  • Elza Fromm-Trinta : Genliseas Americanas. In: Sellowia. Volume 36, 1984, ISSN  0375-1651 , pp. 55-62.
  • Barry A. Meyers-Rice: Are Genlisea traps active? A crude calculation. In: Carnivorous Plant Newsletter. Volume 23, No. 2, 1994, ISSN  0190-9215 , pp. 40-42, ( online ).
  • Eberhard Fischer, Stefan Porembski, Wilhelm Barthlott : Revision of the Genus Genlisea (Lentibulariaceae) in Africa and Madagascar with notes on Ecology and Phytogeography. In: Nordic Journal Of Botany. Volume 20, No. 3, 2000, ISSN  0107-055X , pp. 291-318, doi: 10.1111 / j.1756-1051.2000.tb00746.x .
  • 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. Ulmer, 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 Rafaël Govaerts (ed.): Genlisea. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved December 24, 2018.
  2. ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
  3. ^ Andreas Fleischmann : Monograph of the genus Genlisea. Redfern Natural History Productions Ltd., Poole 2012, ISBN 978-1-908787-00-2 , pp. 266-272.
  4. ↑ Johann Greilhuber, Thomas Borsch, Kai Müller, Andreas Worberg, Stefan Porembski, Wilhelm Barthlott: Smallest angiosperm genome Found in Lentibulariaceae, with Chromosomes of Bacterial size. In: Plant Biology. Volume 8, No. 6, 2006, pp. 770-777, doi: 10.1055 / s-2006-924101 .

further reading

  • Wilhelm Barthlott, Stefan Porembski, Eberhard Fischer, Björn Gemmel: First protozoa-trapping plant found. In: Nature . Volume 392, No. 6675, 1998, p. 447, doi: 10.1038 / 33037 .

Web links

Commons : Reusenfallen ( Genlisea )  - album with pictures, videos and audio files