Corsia

Corsia ornata in situ

Corsia is a little researched plant genus of the family of Corsiaceae. It comprises 25 species, all of which are blattgrünlos and their diet parasitize fungi. Almost all species are endemic to New Guinea.

• 2.1 dissemination
• 2.2 Habitat
• 2.3 myco - heterotrophic
• 2.4 Status and hazard

• 5.1 Literature

Features

In its appearance the species are largely the same except for the flowers. Chromosome numbers are known only from the two types Corsia cornuta and Corsia clypeata; applies to both 2n = 18

Habit

Corsia live largely underground, only rarely trained flower stalk grows above ground. The short, creeping and occupied with reduced whitish, broadly ovate, pointed failed ended stipules rhizome is white to yellowish; the fine, thread-like and hairless root system is also whitish, weakly branched and grows widely extended in all directions, but always close to the surface. From the rhizome sprout several hairless, unbranched and erect flower stems, usually reddish tinge and round in cross section, which are 10 to 28 inches high, the xylem is lignified and not perforated.

The evenly distributed over the stem foliage is three to five annoying stipules reduced broadly ovate and pointed to three to seven, the rhizome are less developed than the reddish stipules on the flower stems. Along the stem, the side leaves grow alternate, at whose approach tightly spiraling. They include the stems almost entirely.

Flowers

The growth of Corsia flowers seem to be triggered by a climatic alternation of rain and drought, usually a longer period of rain, followed by a few days of drought. The zygomorphen and threefold, nodding individual flowers are terminal. They are pale red to red brown colored, sometimes in combination with pale yellow, rarely brownish- green.

The six tepals, with the exception of the uppermost petal, the labellum, of approximately the same shape and size. They are smooth and rarely weakly papillose. The petals of the species of the section are sessilis 4-15 (25) millimeters in length and 0.5 to 2.5 millimeters wide, filiform to linear and hanging, the section Unguiculatis 3 to 8.5 (12) millimeters and a short one to 3.5 mm wide, ovate to oblong and bent back.

The labellum is increased significantly compared to the other petals and usually heart-shaped, it is 5-25 mm long and 4-22 mm wide. The labellum surrounds the upright flower bud and covers after opening the protective other floral organs. The labellum is sometimes traversed by a simple, forked at the top center rib and six to nine pairs of ribs and side is off the calli with fine hairs.

At his approach, the labellum to a large, triangular so-called callus ( " basal callus " ) is thickened, radiating following from warty or lamellar extensions of the Vein of the ( "secondary callus "). The calluses are sometimes hairy or papillose. In the basal callus, there are often additional knot or horn-shaped thickenings. The type of connection between basal callus and gynostemium serves as a diagnostic feature for the separation of the genus into two sections: In the section Unguiculatis the labellum is fused with a ridge of callus tissue on gynostemium in the section sessilis, however, immediately wide at the base of the labellum.

The six edge outgoing from a short, cylindrical pen stamens of hermaphrodite flowers are at the base together and bent the stylus fused to a gynostemium and in the full-blown flower to the outside. The gynostemium is usually between 0.5 and 1 mm long, sometimes up to 1.5 mm ( in C. lamellata 2 to 4 mm). The 0.5 to 1.5 millimeters long, often yellow anthers consist of two departments and open along a longitudinal incision, the button-shaped scars are non grow. The flowers are fully protandrisch by the about 0.5 to 1.5 millimeters in length free stamens are shed during the complete formation of scars.

The long - fusiform ovary is inferior. Because of the widely projecting into the ovary and at times overgrown with each other placentas he is alternately unicompartmental and dreifächrig.

Fruit and seeds

After pollination (possibly by flies ), the flower stems and a yellowish to brown, up to 3.5 centimeters in length long, slender cylindrical capsule fruit forms. Reif it opens along three elongated column, the flaps curl up on to the approach and thus give the placenta freely hung with numerous stalked seeds. The Hawks span shaped seeds between 1 and 3.2 millimeters long, about 0.3 mm thick and pale to dark brown. The seed coat tightly surrounds the endosperm and its surface is grooved fine elongated. Although the habitat is relatively calm, it is assumed that a spread of seeds by wind ( Anemochorie ).

Ecology

Dissemination

The genus has Corsia with 21 of 25 species its center of diversity in New Guinea, but radiates down to the Solomon Islands ( Corsia haianjensis, Corsia pyramidata ), the Bismarck Archipelago ( Corsia purpurata var wiakabui ) and Queensland ( Corsia ornata ) from.

Habitat

They are found mostly in Au or mountain forests at altitudes 400-2700 m and colonize low-light, inaccessible, tiefbödige sites with rich soils with high humidity in dense vegetation. Corsia occurred in the few sightings associated with other myco - heterotrophic plants such Burmannia, Sciaphila and Cotylanthera tenuis on.

Myco - heterotrophy

All species of the genus have abandoned photosynthesis and accordingly form no chlorophyll, instead they live myco -heterotrophic of arbuscular mycorrhizal fungi, are therefore to feed completely from the mushrooms dependent.

Corsia sometimes called Epiparasiten, the term is, however, incorrect: All mykoheterotrophen plants and with them the Corsia are - if known - virtually parasites on fungi: The waxing in the root cells of the Corsia hyphae of the fungus are gradually killed, digested by enzymes and the nutrients stored in the root tissue.

Just as little is known about how the question of whether Corsia are host specific or do not have the involved host species.

Status and risk

In their area of ​​distribution in New Guinea, the species is not demonstrably rare, but many of the species are locally endemic, van Royen wrote: "Almost every mountainrange Seems to have its own species; [ ..] " ( " Nearly every mountain seems to have his own way [.. ] ").

Due to its retracted life and the partial inaccessibility of their habitats currently can not specify a hedged portfolio figures for the species of the genus. However, it is likely that the massive deforestation of the rain forests can at least threaten local endemics in their existence, alone in the Indonesian -controlled western part of the island (size: 422,000 km ²) are for 130,000 km ² logging concessions have been awarded another major areas have been designated as use area.

Botanical history

The first description of the genus in 1877 by Beccari based in 1875 by himself at Mount Morait / Vogelkop collected type Corsia ornata. the genus name honors the former director of the botanical garden of the Villa Corsi Salviati in Florence, the Marchese Bardo Corsi Salviati ( 1844-1907 ).

1905 described Friedrich Richard Rudolf Schlechter in the " addenda to the flora of the German protectorates in the South Seas " two other species of the genus ( Corsia torricellensis, Corsia unguiculata ) and separated at the same time ( as early as 1877, held by Beccari possible ) the family of Corsiaceae of the Burmanniaceae from, to which Hooker and Bentham had it 1883 yet provided. 1912 was followed again by two first descriptions Schlechter and two more in 1946 by Louis Otho Williams.

The most significant contributions to the knowledge of the genus ask Pieter van Royen's monographic work Corsiaceae of New Guinea and surrounding areas from 1972, in which he re- described 14 additional species and performed the subdivision of the genus into two sections sessilis and Unguiculatis and Traudel Rübsamens dissertation Morphological, embryological and systematic studies on Burmanniaceae and Corsiaceae ( with views of the Orchidaceae - Apostasioidae ) 1986 dar.

1998 by Wayne N. Takeuchi and John J. III Pipoly the variety Corsia purpurata var firstdescribed wiakabui. Ten years later it was replaced by D. L. Jones and B. Gray placed in the rank of a species, at the same time, the authors described the new species Corsia dispar.

The genus as a whole is only poorly understood. The majority of all species is known only from one or two collections made, this and the typical for the genus local endemism and its hidden life allow the presumption that there are further, previously unknown taxa. At least one copy is still undescribed ( Corsia spec. I., Clemens 7879 ), it is kept in the Herbarium of the IMA Berlin.

System

The genus is divided into two sections and includes 25 species:

Section Unguiculatis

• Corsia acuminata
• Corsia cornuta
• Corsia dispar
• Corsia purpurata
• Corsia triceratops
• Corsia unguiculata
• Corsia viridopurpurea
• Corsia wiakabui

Section sessilis

• Corsia arfakensis
• Corsia boridiensis
• Corsia brassii
• Corsia clypeata
• Corsia cordata
• Corsia crenata
• Corsia cyclopensis
• Corsia haianjensis
• Corsia huonensis
• Corsia lamellata
• Corsia merimantaensis
• Corsia ornata
• Corsia papuana
• Corsia pyramidata
• Corsia resiensis
• Corsia torricellensis
• Corsia wubungu

Swell

The information in this article originate for the most part the limits given in literature sources, in addition, the following sources are cited: