:"Rachis is also the alternate spelling of Ratchis, king of the Lombards, 744-749."

The rachis (pronEng|ˈreɪkɪs) is the main axis of the inflorescence, or spike, of wheat and other cereals, to which the spikelets are attached. It is also the part of the axis that the pinnae are attached to in ferns, the main stem of a compound leaf (such as in Acacia), or the main axis in compound inflorescences in other angiosperms.

Spikelets are small inflorescences bearing one or more florets, or small flowers, along with a set of miniature bractlike leaves. When the fruits of the wild-type wheat are fully ripened, a series of layers forms that divides the rachis into dispersal units consisting of a single spikelet attached to a short segment of the rachis. A ripe head of wheat is thus easily shattered into dispersal units when touched or blown by the wind. This is referred to by archaeologists as a "brittle rachis".

In animal anatomy, rachis is the series of articulated vertebrae, which encase the spinal cord and forms the supporting axis of the body; the spine. This is also called vertebral column. In feathers, rachis refers to the central shaft.

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  • rachis — [ raʃis ] n. m. • 1575; gr. rhakhis 1 ♦ Anat. Colonne vertébrale, épine dorsale. ⇒ 1. échine. 2 ♦ Sc. nat. Axe d une plume d oiseau. Axe central d un épi. ● rachis nom masculin (grec rhakhis) Synonyme de colonne vertébrale. Axe d une plume d… …   Encyclopédie Universelle

  • Rachis — Saltar a navegación, búsqueda Rachis o Raqui fue duque de Friuli (739 744) y rey de los Lombardos (744 749). Su padre fue Pemmo de Friuli. Se casó con Tassia, una romana. Reinó en paz hasta que sitió, por razones desconocidas, la ciudad de… …   Wikipedia Español

  • Rachis — (Ratchis) (7. Juni), König der Longobarden, welcher den Purpurmantel mit dem Mönchsgewande vertauschte, steht bei Bucelin als »Seliger«. Er bestieg nach dem Jahre 744 für seinen Bruder Luitprand den Königsthron. Als er i. J. 749 Perugia belagerte …   Vollständiges Heiligen-Lexikon

  • Rachis — Ra chis (r[=a] k[i^]s), n.; pl. E. {Rachises} (r[=a] k[i^]s*[e^]z), L. {Rachides} (r[a^]k [i^]*d[=e]z). [NL., fr. Gr. ra chis, ios.] [Written also {rhachis}.] 1. (Anat.) The spine; the vertebral column. [1913 Webster] 2. (Bot. & Zo[ o]l.) Same as …   The Collaborative International Dictionary of English

  • Rachis [1] — Rachis (Bot.), Hauptstiel …   Pierer's Universal-Lexikon

  • Rachis [2] — Rachis, Sohn des Pemmo, 737–744 Herzog von Friaul, dann König der Longobarden …   Pierer's Universal-Lexikon

  • RACHIS — foro Iulii Dux, fil. Remnonis, in locum Aldebrandi seu Hildebrandi, quem vide, nepotis Luitprandi, Longobardorum Rex electus, A. C. 744. Perusium obsedit, A. C. 750. precibus Zachariae Pontificis inde aversus. Postea in gratiam Aistulphi fratris… …   Hofmann J. Lexicon universale

  • rachis — [rā′kis] n. pl. rachises or rachides [rak′ə dēz΄, rā′kədēz΄] [ModL < Gr rhachis, backbone < IE base * wrāĝh , thorn, point > Lith rãžas, stubble] 1. SPINAL COLUMN 2. Bot. the principal axis of an inflorescence or of a compound leaf 3.… …   English World dictionary

  • Rachis — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. Sur les autres projets Wikimedia : « Rachis », sur le Wiktionnaire (dictionnaire universel) Le mot rachis peut renvoyer à : Rachis,… …   Wikipédia en Français

  • rachis — noun (plural rachises; also rachides) Etymology: New Latin rachid , rachis, from Greek rhachis; akin to Greek rhachos thorn, Lithuanian ražas dry twig, tine Date: 1785 1. an axial structure: as a. (1) the elongated axis of an inflorescence (2) an …   New Collegiate Dictionary

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