Corsia
| Corsia | ||||||||||||
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Corsia ornata in situ |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Corsia | ||||||||||||
| Becc. |
Corsia is a little explored plant genus of the family of Corsiaceae . It comprises 25 species, all of which are leaf-green and parasitize fungi for their diet. Almost all species are endemic to New Guinea .
features
Except for the flowers, the species are largely uniform in their appearance. Chromosome numbers are only known for the two species Corsia cornuta and Corsia clypeata ; for both we have 2n = 18.
Habitus
Corsia live largely underground, only the rarely formed flower stalk grows above ground. The short, creeping and with reduced whitish, broad egg-shaped and tapered failed ended stipules occupied rhizome is yellowish white to; the fine, thread-like and hairless roots are also whitish, only weakly branched and grow widely in all directions, but always close to the surface. Several hairless, unbranched and upright flower stalks sprout from the rhizome, mostly with a reddish tinge and round in cross-section, between 10 and 28 centimeters high, the xylem is woody and imperforate.
leaves
The foliage, evenly distributed over the stem, is reduced to three to seven broadly egg-shaped and pointed, three- to five-veined stipules, those of the rhizome are less developed than the reddish stipples on the flower stem. The stipules grow alternately along the stem, at the base of which they are tightly spiraling. They almost completely encompass the stem.
blossoms
The growth of the Corsia flowers seems to be triggered by a climatic interplay of rain and drought, usually a longer period of rain, followed by a few days of drought. The zygomorphic and threefold, nodding single flowers are terminal. They are colored pale red to brownish red, occasionally in combination with pale yellow, rarely brownish green.
The six tepals are, with the exception of the top petal, the labellum , of approximately the same shape and size. They are hairless and rarely have a weak papillae . The petals of the species of the Sessilis section are 4 to 15 (25) millimeters long and 0.5 to 2.5 millimeters wide, thread-like to linear and drooping, those of the Unguiculatis section 3 to 8.5 (12) millimeters short and 1 to 3.5 millimeters wide, ovate to oblong and bent back.
The labellum is considerably larger than the other petals and mostly heart-shaped, it is between 5 and 25 millimeters long and 4 to 22 millimeters wide. The labellum encloses the upright flower bud and, after opening, covers the other flower organs protectively. The labellum is traversed by a simple central rib , occasionally forked at the tip, and six to nine pairs of side ribs , and is finely haired apart from the calli .
At its base, the labellum is thickened into a large, triangular so-called callus (“basal callus”), from which warty or lamellar extensions radiate following the nerve (“secondary callus”). The calluses are occasionally hairy or papillary. In the basal callus there are often additional nodular or horn-shaped thickenings. The type of connection between the basal callus and the gynostemium serves as a diagnostic feature to separate the genus into two sections: In the Unguiculatis section , the labellum is fused with a web of callus tissue on the gynostemium, whereas in the Sessilis section it is directly broad at the base of the labellum.
The six side of the short cylindrical pen outgoing stamens of the hermaphrodite flowers are united at the approach each other and the stylus to a gynostemium and bent at the full bloom bloom to the outside. The gynostemium is usually between 0.5 and 1 millimeter long, occasionally up to 1.5 millimeters (in C. lamellata 2 to 4 millimeters). The 0.5 to 1.5 millimeter long, often yellow anthers consist of two compartments and open along an elongated incision, the button-shaped scars are not overgrown. The flowers are completely protandric in that the stamens , which are more than 0.5 to 1.5 millimeters long, are shed during the full development of the stigmas.
The long-spindle-shaped ovary is subordinate. Because of the placentas that protrude far into the ovary and that have grown together in places , it is alternately single and triple.
Fruits and seeds
After pollination (possibly by flies), the flower stalks elongate and a yellowish to brown, up to 3.5 centimeter long, slender cylindrical capsule fruit forms. When ripe, it opens along three elongated crevices, the flaps roll up to the base, thus releasing the placentas from which the numerous stalked seeds hang. The filet-shaped seeds are between 1 and 3.2 millimeters long, around 0.3 millimeters thick and light to dark brown. The seed coat tightly encloses the endosperm , its surface is finely elongated. Although the habitat is comparatively calm, it is assumed that the seeds will spread through the wind ( anemochory ).
ecology
distribution
With 21 out of 25 species, the genus Corsia has its center of diversity in New Guinea, but extends to the Solomon Islands ( Corsia haianjensis , Corsia pyramidata ), the Bismarck Archipelago ( Corsia purpurata var. Wiakabui ) and Queensland ( Corsia ornata ).
Habitat
They are mostly found in alluvial or mountain forests at altitudes between 400 and 2700 m and colonize light, inaccessible, deep-seated locations with humus soils and high humidity in dense vegetation. During the few sightings, Corsia appeared together with other myco-heterotrophic plants such as Burmannia , Sciaphila and Cotylanthera tenuis .
Myco-heterotrophy
All species of the genus have given up photosynthesis and accordingly no longer form chlorophyll , instead they live myco-heterotrophically on arbuscular mycorrhizal fungi , so they are completely dependent on the fungi for nutrition.
Corsia occasionally as Epiparasiten referred, however, the term is a misnomer: All mycoheterotrophic plants and with them corsia are - if known - almost parasitic on fungi: The in the root cells of corsia waxing hyphae of the fungus are killed by little, by enzymes digested and the nutrients are stored in the root tissue.
Little is known about the host species involved, as well as the question of whether Corsia are host-specific or not.
Status and exposure
The genus is not verifiably rare in its range in New Guinea, but many of the species are locally endemic, van Royen wrote: “Almost every mountain range seems to have its own species; [..] ” (“ Almost every mountain range seems to have its own type, [..] ”).
Due to their withdrawn way of life and the partial inaccessibility of their habitats, no reliable population figures can currently be given for the species of the genus. However, it can be assumed that the massive deforestation of the rainforests can at least endanger the existence of local endemics, in the Indonesian-controlled western part of the island alone (size: 422,000 km²) logging concessions have been granted for 130,000 km², other large areas are designated as areas of use.
Botanical history
The genus was first described in 1877 by Beccari using the species Corsia ornata, which he himself collected on Mount Morait / Vogelkop in 1875 . the generic name honors the then head of the botanical garden of the Villa Corsi Salviati in Florence, the Marchese Bardo Corsi Salviati (1844–1907).
In 1905, Friedrich Richard Rudolf Schlechter described two further species of the genus ( Corsia torricellensis , Corsia unguiculata ) in the "Supplements to the Flora of the German Protected Areas in the South Seas" and at the same time separated the Corsiaceae family from the family (as Beccari thought possible as early as 1877) Burmanniaceae , to which Hooker and Bentham had put them in 1883. In 1912 there were two first descriptions by Schlechter and two more in 1946 by Louis Otho Williams .
The most important contributions to knowledge of the genus are made by Pieter van Royen's monographic work Corsiaceae of New Guinea and surrounding areas from 1972, in which he described 14 further species and divided the genus into the two sections Sessilis and Unguiculatis , as well as Traudel Rübsamen's dissertation Morphological , embryological and systematic studies on Burmanniaceae and Corsiaceae (with a view of the Orchidaceae-Apostasioidae) from 1986.
The variety Corsia purpurata var. Wiakabui was first described in 1998 by Wayne N. Takeuchi and John J. Pipoly III . Ten years later it was given the rank of a species by DL Jones and B. Gray, at the same time the authors described the new species Corsia dispar .
The genus has been little researched overall. The majority of all species are only known from one or two collections, this and the local endemism typical for the genus as well as their hidden way of life allow the assumption that other, previously unknown taxa exist. At least one specimen is currently still unwritten ( Corsia spec. I, Clemens 7879), it is kept in the herbarium of the BGBM Berlin .
Systematics
The genus is divided into two sections and includes 25 species:
Section Unguiculatis P. Royen
- Corsia acuminata L.O.Williams
- Corsia cornuta P.Royen
- Corsia dispar D.L. Jones & B.Gray : It occurs in northern Queensland.
- Corsia purpurata L.O.Williams
- Corsia triceratops P.Royen
- Corsia unguiculata Schltr.
- Corsia viridopurpurea P.Royen
- Corsia wiakabui (WNTakeuchi & Pipoly) DLJones & B.Gray
Section Sessilis P. Royen
- Corsia arfakensis Gibbs
- Corsia boridiensis P.Royen
- Corsia brassii P. Royen
- Corsia clypeata P.Royen
- Corsia cordata Schltr.
- Corsia crenata J.J.Sm.
- Corsia cyclopensis P.Royen
- Corsia haianjensis P.Royen
- Corsia huonensis P.Royen
- Corsia lamellata Schltr.
- Corsia merimantaensis P.Royen
- Corsia ornata Becc.
- Corsia papuana P.Royen
- Corsia pyramidata P.Royen
- Corsia resiensis P.Royen
- Corsia torricellensis Schltr.
- Corsia wubungu P.Royen
Individual evidence
- ^ Paul Kores, David A. White, Leonard B. Thien: Chromosomes of Corsia (Corsiaceae) , American Journal of Botany, Vol. 65, no. 5 (May-Jun., 1978), pp. 584-585, ISSN 0002-9122
- ↑ Kirkbride, JH, Jr., CR Gunn, and MJ Dallwitz: Family Guide for Fruits and Seeds , Vers. 1.0, 2006, accessed on: March 26, 2007, online ( Memento of October 7, 2007 in the Internet Archive )
- ↑ C. Neinhuis, P. Ibisch: Corsiaceae , in: K. Kubitzki (Ed.): The Families and Genera of Vascular Plants, Vol. 3, Lilianae. P. 200, 1998, ISBN 3-540-64060-6 :
- ↑ Phillip Cribb: The saprophytic genus Corsia in the Solomon Islands , in: The Kew Magazine, 2/1985, pp. 320-323, ISSN 0265-3842
- ^ Australian National Botanic Gardens, Australian National Herbarium: Australian Plant Name Index (APNI) of the Integrated Botanical Information System (IBIS) , entry online
- ↑ Laura S. Dominguez, Alicia Sersic: The southernmost myco-heterotrophic plant, Arachnitis uniflora: root morphology and anatomy , in: Mycologia, 2004, 96, pp. 1143-1151, ISSN 0027-5514
- ↑ P. Van Royen: Sertulum Papuanum 17. Corsiaceae of New Guinea and surrounding areas. in: Webbia 27, 1972, p. 230, ISSN 0083-7792 .
- ^ International Crisis Group: Resources and Conflict in Papua. , Brussels, 2002 Online ( Memento of April 1, 2005 in the Internet Archive )
- ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
- ↑ DLJones, B.Gray: Corsia dispar DLJones & B.Gray (Corsiaceae), a new species from Australia, and a new combination in Corsia for a New Guinea taxon. In: Austrobaileya 7 (4): 719-721, 2008
- ↑ Traudel Rübsamen: Morphological, embryological and systematic studies on Burmanniaceae and Corsiaceae (with a view of the Orchidaceae-Apostasioideae) , p. 17
- ^ R. Govaerts: World Checklist of Corsiaceae , The Board of Trustees of the Royal Botanic Gardens, Kew, 2013, accessed January 27, 2013, 12:23 pm, online
- ↑ a b Rafaël Govaerts (ed.): Corsia. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved June 26, 2018.
literature
- P. Van Royen: Sertulum Papuanum 17. Corsiaceae of New Guinea and surrounding areas. in: Webbia 27: pp. 223-255, 1972, ISSN 0083-7792 .
- Traudel Rübsamen: Morphological, embryological and systematic studies on Burmanniaceae and Corsiaceae (with a view of the Orchidaceae-Apostasioideae). 1986, ISBN 3-443-64004-4 .
- Paula J. Rudall, Alison Eastman: The questionable affinities of Corsia (Corsiaceae): evidence from floral anatomy and pollen morphology. in: Botanical Journal of the Linnean Society, 138, 2002, pp. 315-324.
- Karl Schumann , Karl Lauterbach : Supplements to the flora of the German protected areas in the South Seas with the exclusion of Samoa and the Carolines. Leipzig 1905, online version .
- Rudolf Schlechter : New Corsiaceae Papua. in: Botanical Yearbooks for Systematics, Plant History and Plant Geography, Vol. 49, Stuttgart 1913, pp. 109–112 online version .
- Dianxiang Zhang , Richard MK Saunders, Chi-Ming Hu: Corsiopsis chinensis gen. Et sp. nov. (Corsiaceae): First Record of the Family in Asia. in: Systematic Botany, Vol. 24, No. 3 (Jul-Sep, 1999), pp. 311-314, ( Abstract Online ).
