Pachyplectron

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Pachyplectron
Systematics
Order : Asparagales (Asparagales)
Family : Orchids (orchidaceae)
Subfamily : Orchidoideae
Tribe : Cranichideae
Sub tribus : Goodyerinae
Genre : Pachyplectron
Scientific name
Pachyplectron
Schltr.

The genus pachyplectron from the family of orchids consists of three types . They only occur in New Caledonia .

description

The Pachyplectron species are herbaceous , terrestrial plants. The roots are fleshy, smooth or hairy. They stand together in clusters, not individually distributed along a rhizome . The one to three basal leaves are long stalked. The leaf blade is arrow-shaped to elliptical in shape. The leaf color is reddish brown, brown or green. In pachyplectron aphyllum , a mycoheterotrophic way missing the leaves.

The terminal inflorescence is unbranched. The inflorescence axis, bracts , ovary and the outside of the sepals are hairy or hairless depending on the species. There are some bracts on the peduncle ; the bracts of the flowers are about as long as the flower stalk and ovary together. The flowers are resupinated , they do not open wide. The upward-pointing sepal is concave or slightly dome-shaped. The lateral sepals are elongated-elliptical, somewhat asymmetrical, the base running down from the ovary includes the spur of the lip . The lateral inner petals ( petals ) are narrower and stick with the edge to the upper sepal. The lip has a cylindrical spur at the base that is parallel to the ovary. The blade of the lip is undivided, concave, it ends cut off in front. The column is long and club-shaped. The scar consists of a contiguous, heart-shaped to triangular area. The stamen is oval to kidney-shaped in outline, it contains two pollinia that are deeply divided into two parts. The consistency of the pollinia is soft and floury, they are connected with a small, round adhesive disc ( Viscidium ). There are fruit capsules formed.

distribution

Pachyplectron is common in New Caledonia with three types. The species grow in the shade of evergreen rainforests, in sparse forests and bushes, at altitudes of 100 to 1200 meters.

Botanical history and systematics

Pachyplectron was described by Rudolf Schlechter in 1906 with the type species Pachyplectron arifolium . The name is derived from the Greek word pachys , "thick" and plectron , "spur". Schlechter set up a separate subtribe Pachyplectroninae for this genus , as he regarded them as isolated from the family. Dressler kept this subtribe, placed it in the tribe Cranichideae and considered a relationship with the Spiranthinae and Manniella possible. According to DNA studies, Pachyplectron is the sister taxon to all other Goodyerinae and can be included in this subtribe.

The following species are included in the genus Pachyplectron :

See also

literature

  • Nicolas Hallé: Orchidacées . In: A. Aubréville, Jean-F. Leroy (Ed.): Flore de la Nouvelle-Calédonie . tape 8 , 1977, ISBN 2-85654-152-6 , pp. 506-511 .
  • Tamotsu Hashimoto: The third species of the genus Pachyplectron Schltr., Orchidaceae . In: Annals of the Tsukuba Botanical Garden . tape 16 , 1997, pp. 7-10 .
  • Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (Eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3 . Oxford University Press, New York / Oxford 2003, ISBN 0-19-850711-9 , pp. 131-134 .
  • Rudolf Schlechter: Contributions to the knowledge of the flora of New Caledonia . In: Adolf Engler (Ed.): Botanical yearbooks for systematics, plant history and plant geography . tape 39 . Wilhelm Engelmann, Leipzig 1906, p. 51 ( archive.org ).
  • Société Néo-Calédonienne d'Orchidophilie (Ed.): Orchidées indigènes de Nouvelle-Calédonie . 1995, ISBN 2-9509530-0-X , pp. 138-139 .

Individual evidence

  1. ↑ a b c d e f g Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3 . Oxford University Press, New York / Oxford 2003, ISBN 0-19-850711-9 , pp. 131-134 .
  2. ^ A b Nicolas Hallé: Orchidacées . In: A. Aubréville, Jean-F. Leroy (Ed.): Flore de la Nouvelle-Calédonie . tape 8 , 1977, ISBN 2-85654-152-6 , pp. 506-511 .
  3. ↑ a b Rafaël Govaerts (Ed.): Pachyplectron. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved March 28, 2020.
  4. ^ Robert L. Dressler: Phylogeny and Classification of the Orchid Family . Cambridge University Press, Cambridge 1993, ISBN 0-521-45058-6 , pp. 122 .

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