Degranvillea dermaptera
| Degranvillea dermaptera | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Degranvillea | ||||||||||||
| Determann | ||||||||||||
| Scientific name of the species | ||||||||||||
| Degranvillea dermaptera | ||||||||||||
| Determann |
The orchid Degranvillea dermaptera is the only species in the genus Degranvillea within the orchid family (Orchidaceae). It was only found in French Guiana . It is Mykoheterotrophie ago.
description
Degranvillea dermaptera grows as a perennial herbaceous plant . It forms a rootless, strongly branched, bulbous, thickened, hairy rhizome underground . Above ground, of the approximately 15 cm high appears inflorescence , leaves are not formed.
The inflorescence axis is hairy, unbranched, upright , slightly overhanging in the upper area, where the flowers are located. The color of the shoot is whitish, it is tubularly surrounded by small, lanceolate, slightly orange bracts . In the lower area of the shoot, some bracts are so dense that they overlap, further up the internodes are longer so that they are spaced apart. The flowers are huddled in two to five, they open at the same time. The carrier sheets are 5 to 7 mm long, pedicel and ovary measured along 1 to 1.5 cm, wherein the flower stem is relatively long. The flowers are whitish, slightly hairy, horizontally protruding and tubular. The petals are 5.5 to 6 mm long and 1.5 to 2 mm wide. The two lateral sepals are fused together and form a 6 to 7 mm long, conical spur. The lip is strongly narrowed at the base for a short piece that is fused with the lateral sepals, there with two lateral, 3 mm long, thread-like appendages directed backwards into the spur, which secrete nectar. Towards the front, the lip becomes wider in the shape of a wedge, it is wrapped around the column in a semicircle in cross section. The front third is spread out, turned down a bit and curled at the edge. The lip measures 7 × 5 mm. The yellowish white column is slightly wider in the shape of a club towards the front, it is not curved and has a longitudinal furrow on the underside. The stamen contains two granular pollinia , which are connected to the front (apical) with a round adhesive disc ( Viscidium ). The scar consists of two separate surfaces. The separating tissue between the stigma and the stamen ( rostellum ) is wide and ends bluntly cut off.
distribution
Degranvillea dermaptera is endemic to French Guiana . It grows in the humus layer of forests at altitudes of 400 to 650 meters. The climate is characterized by a short dry period.
Systematics and botanical history
Degranvillea dermaptera was first collected in 1979 by Determann and Jean Jacques de Granville. Determann established a new genus in his first description in 1985 and named it after Jean Jacques de Granville (born 1943), a French botanist. The specific epithet dermaptera is derived from the scientific name of the earwigs , as the appendages of the lip are reminiscent of their cerci .
According to morphological criteria Degranvillea dermaptera is classified within the orchids (Orchidaceae) in the subtribe Spiranthinae from the tribe Cranichideae in the subfamily Orchidoideae within the family Orchidaceae . The further relationships are unclear. Degranvillea differs from the other genera of the Spiranthinae by the thread-like nectar glands, the long flower stalk and the shape of the rostellum.
Individual evidence
- ^ A b c d Ronald O. Determann: Degranvillea - A New Orchid Genus From French Guiana . In: American Orchid Society Bulletin . tape 54 , no. 2 , 1985, pp. 174-176 .
- ↑ a b c Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3/2 . Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9 .
- ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. doi : 10.3372 / epolist2018