Brachypodium

Pinna - Zwenke ( Brachypodium pinnatum )

The Zwenken ( Brachypodium ) is a genus of grasses ( Poaceae ).

• 5.1 Notes and references

Description

Vegetative characteristics

The Zwenken are usually perennial, rare (only Brachypodium distachyon ) one-year, horst- or carpet-forming grasses. Most species have rhizomes. You can have underground runners. The non-flowering shoots grow intra-or extravaginal up. The stems are erect or geniculate - ascending and are more knotty. The stems are hairy nodes, internodes hollow. The vascular bundles in the internodes are available in three circles. The stalks are 2 to 200 inches high.

The leaf sheaths are open to the bottom. The ligule is tongue- or collar -shaped, and truncated or rounded. The leaf blade is rolled in bud position, otherwise flat - spread. The leaf surface is glabrous or hairy. The vascular bundles cause a ribbing of the leaf surface. The midrib does not produce prominent. The sclerenchyma is always associated with the vascular bundles.

Generative features

The inflorescence is a loose cluster with one to twelve spikelets. These are short ( 0.5 to 3 mm) stalked, two - or allseitswendig. You are projecting or adjacent, alternate and use the wide side of the ears axis. The spikelet has 3 to 60 flowers. All are hermaphroditic. The florets fall for fruit ripening individually from the glumes are permanent. The glumes are unequal, pointed, or with a short awn grannenspitzig. The lower glume is three to seven nerves. The lemmas are five to nine annoying, entire above, and pointed or tapering to an awn. The awn straight or tortuous. The palea are two annoying and somewhat shorter than the lemmas.

The Zwenken have three stamens with anthers 1-6 mm long. The ovary is filled up with short hair. He has two terminal, short stylus and a long, feathery stigma. All types except Brachypodium distachyon show self-incompatibility.

The fruit ( caryopsis ) has a narrow elliptical outline. It is narrow at the top hautrandig, crescent-shaped in cross section. The embryo takes about one fifth of the fruit length. The endosperm is hard, fat-free and consists of simple starch grains. The navel spot ( hilum ) is linear and about as long as the fruit.

Chromosome number

The basic chromosome number is x = 5, 7, 9 and 10 plants are di -, tetra-, hexa-and oktoploid with chromosome numbers of 2n = 10, 14, 16, 18, 28, 30, 42, or 56

Dissemination

The Zwenken are particularly common in the temperate regions and in tropical mountains. They occur in the Holarctic, the Paläotropis, Neotropics and capensis. Often they also occur adventiv. You are mesophytisch. However, they grow to a shady sites, other types of open spots.

System

Brachypodium is derived from the Greek brachys = short, and pous, plural podes = foot. The name refers to the short -stalked spikelets.

The genus is within the grasses in the subfamily Pooideae and alone forms the tribe Brachypodieae. The genus is quite at the base of the subfamily Pooideae and is monophyletic.

In Central Europe the pinna - Zwenke are ( Brachypodium pinnatum ), the Rock Zwenke ( Brachypodium rupestre ) and the forest Zwenke ( Brachypodium sylvaticum ) native. In Europe and the Mediterranean region, the following species occur:

• Brachypodium arbuscula Knoche, endemic to the Canary islands of Tenerife, La Gomera and El Hierro.
• Brachypodium atlanticum Dobignard
• Brachypodium boissieri Nyman, in southern Spain, is closely related with B. retusum.
• Brachypodium distachyon (L.) Beauv P., Syn Trachynia distachya (L.) Link, home. Mediterranean, Canary Islands, Cape Verde, Ethiopia, Middle East and Central Asia, naturalized in South Africa, Australia, North and South America, inconstant in Central Europe occurring.
• Brachypodium gaditanum Talavera
• Brachypodium genuense ( DC.) Roem. & Schult.
• Brachypodium glaucovirens ( Murb. ) Sagorski, Brachypodium sylvaticum subsp Syn. glaucovirens Murb. The Heimatis t the Mediterranean area; it is closely related with B. sylvaticum.
• Brachypodium kotschyi Boiss.
• Brachypodium phoenicoides (L.) Roem. & Schult. Homeland: Western Mediterranean region, naturalized in Upper Bavaria.
• Pinna - Zwenke ( Brachypodium pinnatum (L.) Beauv P.. ), Eurasian spread, including in Algeria.
• Brachypodium retusum (Pers. ) P. Beauv. , Widespread in the Mediterranean area.
• Rock Zwenke ( Brachypodium rupestre (Host) Roem. & Schult. ), In temperate and meridional Europe and Western Asia. Brachypodium rupestre subsp. cespitosum (Host) H. Scholz
• Brachypodium rupestre subsp. rupestre

Other types are:

• Brachypodium bolusii Stapf: South and East Africa.
• Brachypodium Flexum Nees: South and East Africa, without a secured species status.
• Brachypodium japonicum Miq. Possibly belonging to B. sylvaticum.
• Brachypodium kawakamii Hayata: endemic to Taiwan.
• Brachypodium mexicanum ( Rom. & Schult. ) Link: Mexico to Bolivia.
• Brachypodium pringlei Scribner ex Beal: Central and South America, without a secured species status.

Genetic studies have revealed the following cladogram, but all types were not represented:

B. sylvaticum

B. pinnatum

B. phoenicoides

B. rupestre

B. retusum

B. arbuscula

B. mexicanum

B. distachyon

At the base so is the annual species Brachypodium distachyon, which is often separated in the genus Trachynia. Next, the Mexican Brachypodium branches mexicanum, a type without rhizomes. The remaining species are the rhizomtragenden perennial species.

Relevance to humans

The Zwenken have no economic significance. However, Brachypodium distachyon is a not insignificant weeds and stands as a more grass - model plant (besides rice) with the fully sequenced genome available.

Sources and further information

• Pilar Catalán, Richard G. Olmstead: Phylogenetic reconstruction of the genus Brachypodium P. Beauv. ( Poaceae ) from combined sequences of chloroplast ndhF gene and nuclear ITS. In: Plant Systematics and Evolution. Volume 220 ​​, No. 1-2, 2000, pp. 1-19, DOI: 10.1007/BF00985367.
• Manfred A. Fischer, Wolfgang Adler, Karl Oswald: Exkursionsflora for Austria, Liechtenstein and South Tyrol. Second, improved and expanded edition. Province of Upper Austria, Biology Centre of the Upper Austrian State Museums, Linz 2005, ISBN 3-85474-140-5, p 1179.
• Uwe Schippmann: Revision of the European species of the genus Brachypodium Palisot de Beauvois ( Poaceae ). In: Boissiera. Volume 45, 1991, pp. 1-250.
• Siegmund Seybold (ed.): Schmeil - Fitschen interactive. CD -ROM, Version 1.1, Quelle & Meyer, Wiebelsheim 2002, ISBN 3-494-01327-6.
• L. Watson, M. J. Dallwitz: The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: November 28, 2005 ( URL). .
• Walter Erhardt, Erich Götz, Nils Boedeker, Siegmund Seybold: The big walleye. Encyclopedia of plant names. Volume 2 species and varieties. Eugen Ulmer, Stuttgart 2008, ISBN 978-3-8001-5406-7, p 1252.