Ancistrorhynchus

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Ancistrorhynchus
Ancistrorhynchus metteniae (fig. II 9-15) Heinrich Gustav Reichenbach: Xenia Orchidacea

Ancistrorhynchus metteniae (fig. II 9-15)
Heinrich Gustav Reichenbach :
Xenia Orchidacea

Systematics
Order : Asparagales (Asparagales)
Family : Orchids (orchidaceae)
Subfamily : Epidendroideae
Tribe : Vandeae
Sub tribus : Aerangidinae
Genre : Ancistrorhynchus
Scientific name
Ancistrorhynchus
Finet

The genus ancistrorhynchus from the family of the orchid (Orchidaceae) consists of 17 species . The plants usually grow epiphytically , they occur in tropical Africa.

description

The Ancistrorhynchus species have a monopodial , rarely branched stem axis . This is compressed with short internodes . The shoots sometimes grow upright, often hanging down in an arch. In the lower area there are the roots covered by velamen . The leaves sit in two rows on the shoot and are separated from this by a separating fabric. The leaf base encompasses the shoot in such a way that it is completely covered by the leaf bases. They unfold conduplicate , the midrib stands out clearly. The shape of the leaves is linear to lanceolate. The tip of the leaf is drawn in so that two lobes are created. These are almost the same to significantly different in size, rounded, pointed or provided with several teeth. In small species, such as Ancistrorhynchus parviflorus , the leaves measure only four centimeters in length, while in Ancistrorhynchus clandestinus they are up to a meter long.

The flowers are densely packed in short inflorescences . The paper-like bracts can be as large as the flowers. The predominant flower color is white, sometimes a little greenish or brownish. The flowers only last a few days and often remain half closed. You are resupinated with some species , but not with others. The petals are not fused together. The lip is simple or slightly three-lobed and forms a spur at its base. The column bears the slightly sunken stigma on the underside and the stamen at the end . The dividing tissue between the stamen and the stamen (rostellum) is in two parts, the two long lobes lead away from the stamen, first parallel to the column and then bend 180 ° towards the tip of the column. The two pollinia are connected by a common or two separate stalk with a common adhesive disc (Viscidium).

distribution

The species of the genus Ancistrorhynchus are common in tropical Africa, especially in the west. Ancistrorhynchus metteniae has the largest distribution area from Sierra Leone over Nigeria , the Central African Republic and Uganda to Ethiopia and Tanzania .

They are epiphytic plants growing in the shade of ever-moist forests.

Systematics and botanical history

The genus Ancistrorhynchus was established in 1907 by Achille Finet . The two species he named were Ancistrorhynchus breviflorus and Ancistrorhynchus recurvus . Long before that, John Lindley and Heinrich Gustav Reichenbach had described three species - in the genera Angraecum and Listrostachys  - which Finet did not recognize as belonging to his new genus. Only Rudolf Schlechter summed up 1918 these five species, but provided a genus same Cephalangraecum for species with strong swamped inflorescence axis on. This was united by Summerhayes in 1944 with Ancistrorhynchus . The name Ancistrorhynchus was formed from the Greek words ἄγκιστρον "ankistron" for 'hook' and ῥύγχος "rhynchos" for 'beak'. It refers to the hook-shaped rostellum.

The genus belongs to the tribe Vandeae . For a long time it was placed in a subtribe Aerangidinae with several other genera . However, more recent works favor the amalgamation under a broad subtribe Angraecinae . The genera Bolusiella and Microcoelia are closely related .

The following species are included in the genus Ancistrorhynchus :

See also

literature

  • Joyce Stewart: Angraecoid orchids, Species from the African region . Timber Press, Portland Or 2006, ISBN 0-88192-788-0 .
  • Isobyl la Croix, Phillip Cribb: Orchidaceae. In: Flora Zambesiaca . tape 11 , no. 2 . London 1998.

Web links

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

Individual evidence

  1. ↑ Barbara S. Carlsward, W. Mark Whitten, Norris H. Williams, Benny Bytebier: Molecular phylogenetics of Vandeae (Orchidaceae) and the evolution of leaflessness . In: American Journal of Botany . tape 93 , no. 5 , 2006, ISSN  0002-9122 , p. 770-786 .
  2. ↑ Rafaël Govaerts (ed.): Ancistrorhynchus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 4, 2020.