Eurycentrum

Eurycentrum
	Eurycentrum obscurum (A, left) and Eurycentrum salomonense (B, right), illustration from Karl Moritz Schumann , Karl Lauterbach : "Supplements to the flora of the German protected areas"
Systematics
Order :	Asparagales (Asparagales)
Family :	Orchids (orchidaceae)
Subfamily :	Orchidoideae
Tribe :	Cranichideae
Sub tribus :	Goodyerinae
Genre :	Eurycentrum
Scientific name
	Eurycentrum
	Schltr.

Eurycentrum is a genus from the family of the orchid (Orchidaceae). It consists of seven types of herbaceous plants that are native to New Guinea and neighboring islands.

description

The species of the genus Eurycentrum form a creeping rhizome , the roots are hairy. The few leaves are slightly asymmetrical, oval-lanceolate to rounded. The base of the leaves is narrowed to a short petiole, the base of the leaf includes the stem in a tubular shape. The leaves are dark in color, reddish to greenish-brown.

The inflorescence is a terminal cluster . The inflorescence axis, the bracts of the flowers, the ovary and the outside of the three outer petals are hairy. There are some bracts on the peduncle . The bracts are as long as ovary and pedicel together. The ovary is twisted, the flowers are resupinated . The lateral sepals adhere to the lip , at the base they can be asymmetrically expanded, but not concave. The third, dorsal sepal is somewhat smaller than the lateral sepals. The lateral petals are obliquely elongated-elliptical, they adhere to the upper petal. The lip forms an almost cylindrical or conical spur at the base. In the spur there is a rounded appendage on each side. The middle part of the lip is U-shaped in cross-section as the sides are turned up; if you spread it out, you get a broad oval shape. The front part of the lip is entire or bilobed. Two side lamellas run along the column. The kidney-shaped to broadly oval stamen is two-chambered. The pollinia are inverted egg-shaped or divided lengthways in two. They are directly connected to a round adhesive disc ( Viscidium ) without a stalk , some species have a short stalk and a triangular adhesive disc. The scar consists of two interconnected surfaces. The separating tissue between the stigma and the stamen (rostellum) is short, and after removing the adhesive disc it is only cut flat at the tip.

Occurrence

Eurycentrum is located in New Guinea and the Bismarck Archipelago , only Eurycentrum salomonense occurs in the Solomon Islands , the Santa Cruz Islands and Vanuatu . Altitudes from sea level to 2,300 meters are populated. Eurycentrum species grow in the humus layer of moist forests.

Systematics and botanical history

Eurycentrum is classified within the tribe Cranichideae in the subtribe Goodyerinae . According to Dressler, this can be further divided into two groups; Eurycentrum stands in the larger group with a scar surface.

The genus Eurycentrum was established in 1905 by Rudolf Schlechter . The name is made up of the Greek words εὐρύς eurys , "broad", and κέντρον kentron , "sting, spur"; it refers to the broad, conical spur of the two species Schlechter was first aware of. The type species is Eurycentrum obscurum . In another publication in 1911 Schlechter described two other species.

There are currently four in Eurycentrum :

Eurycentrum fragrans Schltr. : Papua New Guinea .
Eurycentrum monticola Schltr. : Papua New Guinea.
Eurycentrum obscurum (flower) Schltr. (Syn .: Eurycentrum amblyoceras > Schltr. , Eurycentrum atroviride J.J.Sm. , Eurycentrum goodyeroides Ridl. ): New Guinea to the Bismarck Archipelago
Eurycentrum salomonense Schltr. : Papua New Guinea to Vanuatu .

Individual evidence

↑ ^a ^b ^c ^d ^e 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. 90-91 .
^ ^A ^b Rudolf Schlechter: Orchidaceae . In: K. Schumann, K. Lauterbach (Hrsg.): Supplements to the flora of the German protected areas in the South Seas . 1905, p. 89-90 ( Botanicus ).
↑ ^a ^b ^c ^d ^e ^f Rafaël Govaerts (Ed.): Eurycentrum. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved March 27, 2020.
^ Robert L. Dressler: Phylogeny and Classification of the Orchid Family . Cambridge University Press, 1993, ISBN 0-521-45058-6 , pp. 118 .
^ Rudolf Schlechter: The Orchidaceae of German New Guinea . In: Repertorium specierum novarum regni vegetabilis. Booklets . tape 1 , 1911, p. 62-65 ( Biodiversity Heritage Library ).

Web links

Commons : Eurycentrum - album with pictures, videos and audio files

List of orchid genera

[GO3-1] 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. 90-91 .

[Schlechter1905-2] A ^b Rudolf Schlechter: Orchidaceae . In: K. Schumann, K. Lauterbach (Hrsg.): Supplements to the flora of the German protected areas in the South Seas . 1905, p. 89-90 ( Botanicus ).

[WCSP-3] ↑ ^a ^b ^c ^d ^e ^f Rafaël Govaerts (Ed.): Eurycentrum. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved March 27, 2020.

[Dressler-4] Robert L. Dressler: Phylogeny and Classification of the Orchid Family . Cambridge University Press, 1993, ISBN 0-521-45058-6 , pp. 118 .

[Schlechter1911-5] Rudolf Schlechter: The Orchidaceae of German New Guinea . In: Repertorium specierum novarum regni vegetabilis. Booklets . tape 1 , 1911, p. 62-65 ( Biodiversity Heritage Library ).