Arachnis (orchid)

Arachnis LabROSA

The genus Arachnis from the orchid family (Orchidaceae ) consists of eleven species. The plants grow as epiphytes, they are found in tropical Asia. Used were the species - especially Arachnis hookeriana - often for the cultivation of orchids hybrids for cut flower production.

Description

The Arachnis species grow monopodial with occasional branches. The shoot axis is often stretched liane -like, in some species, the internodes are not as long and the shoot growing erect or pendulous. The roots are usually distributed along the stem axis, sometimes only the bottom. The leaves are arranged in two rows, long - oval to band-shaped, slightly bilobed by a retracted top. The inflorescences arise laterally from the leaf axils at the top of the rung. There are grapes or panicles, usually protrudes above the leaves. The petals are not fused together, spread wide and meaty texture. Except for the lip petals are shaped equal to each other - very narrow obovate or spatulate. The small lip forms at the base of a spur and at this point is articulated with the short extension of the column ( column base ) grow together. The lamina of the lip is three-lobed, the lateral lobes small stand upright and the middle lobe is occupied by a longitudinal callus. At the end of the short, compact column is the stamen with four pollinia in two pairs.

Dissemination

The species of the genus Arachnis are widespread in tropical Asia. In the northwest, the area extends up to Bhutan and Sikkim, to the southeast southern China, Indo-China, the Philippines and Borneo is populated, the area extends to New Guinea and the Solomon Islands.

There are epiphytic plants growing more humid and seasonally dry tropical forests.

Systematics and botanical history

The genus Arachnis is counted for subtribe Aeridinae. Intersections with numerous allied genera, as Ascocentrum, Phalaenopsis, Vanda and Renanthera were realized.

Carl Ludwig Blume already described the genus in 1825. The name derives from the Greek " arachne " for " spider " and refers to the shape of the flower.

The following eleven species are known:

  • Arachnis annamensis ( Rolfe ) J.J.Sm.
  • Arachnis beccarii Rchb.f. Arachnis beccarii beccarii var
  • Arachnis beccarii var imthurnii ( Rolfe ) K.W.Tan
  • Arachnis flos- aeris var flos- aeris
  • Arachnis flos- aeris var gracilis Holttum

The hybrids from Arachnis flos- aeris Arachnis × hookeriana is Arachnis × maingayi ( Hook.f. ) Schltr. mentioned.

Documents

The information of this article come from mainly:

  • Jim B. Comber: Orchids of Java. Bentham - Moxon Trust, Kew, 1990, ISBN 0-947643-21-4, pp. 324-325.
  • Xinqi Chen, Zhu Guanghua, Ji Zhanhe, long Kaiyong, Luo Yibo, Phillip Cribb: Orchidaceae (draft ). In: Wu Zhengyi, Peter H. Raven (eds.): Flora of China. Missouri Botanical Garden Press, St. Louis 1994 ( eFloras.org, accessed on 06.08.2008 ).

Moreover, quoting:

Epidendroideae Labellum (botany) Pollinium Farther India
74045
de