cotyledon


cotyledon
cotyledonal, cotyledonary /kot'l eed"n er'ee/, cotyledonous, adj.
/kot'l eed"n/, n. Bot.
1. the primary or rudimentary leaf of the embryo of seed plants.
2. Anat. any of several lobules of the placenta.
[1535-45; < L: navelwort < Gk kotyledón a plant (prob. navelwort), lit., a cuplike hollow, deriv. of kotýle cup]

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Seed leaf within the embryo of a seed that provides energy and nutrients for the developing seedling.

After the first true leaves have formed, they wither and fall off. Flowering plants whose embryos have a single cotyledon are grouped as monocots, or monocotyledonous plants; embryos with two cotyledons are grouped as dicots, or dicotyledonous plants. Unlike flowering plants, gymnosperms usually have several cotyledons rather than one or two.

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      seed leaf within the embryo of a seed. Flowering plants whose embryos have a single cotyledon are grouped as monocots, or monocotyledonous plants; embryos with two cotyledons are grouped as dicots, or dicotyledonous (dicotyledon) plants. The number of cotyledons in the embryos of seeds of gymnosperms is highly variable, ranging from 8 to 20 or more.

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Universalium. 2010.

Look at other dictionaries:

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  • cotylédon — [ kɔtiledɔ̃ ] n. m. • 1534; cotillidones 1314; gr. kotulêdon « creux, cavité » → cotyle 1 ♦ Embryol. Chacun des segments polygonaux, délimités par des cloisons, à la surface utérine du placenta humain ou animal. 2 ♦ (XVIIIe) Bot. Feuille… …   Encyclopédie Universelle

  • Cotyledon — Cotylédon Les deux cotylédons d une graine de Jacaranda mimosifolia en phase de germination Les cotylédons (scientifiquement nommés feuilles cotylédonaires) sont les feuilles primordiales constitutives de la graine. Le terme vient du grec… …   Wikipédia en Français

  • cotyledon — from 1540s, in various sense, from L. cotyledon pennywort, navelwort, from Gk. kotyledon cup shaped cavity, from kotyle hollow thing, small vessel, also the name of a small liquid measure (nearly a half pint); of uncertain origin. Botanical sense …   Etymology dictionary

  • Cotyledon — Cot y*le don (k?t ? l? d?n), n. [Gr.??? a cupshaped hollow, fr. ???. See {Cotyle}.] 1. (Anat.) One of the patches of villi found in some forms of placenta. [1913 Webster] 2. (Bot.) A leaf borne by the caulicle or radicle of an embryo; a seed leaf …   The Collaborative International Dictionary of English

  • Cotylēdon — (C. L.), Pflanzengattung aus der Familie der Crassulaceae Crassuleae Diplostemones Umbiliceae, 5. Ordn. 6. Kl.L. Arten: C orbiculata, mit flachen, spatelförmigen, fleischigen, mehligen, gegenüberstehenden Blättern, rispenständigen, rothen Blüthen …   Pierer's Universal-Lexikon

  • Cotylĕdon — Dec. (Nabelkraut), Gattung der Krassulazeen, Kräuter oder Halbsträucher von sehr verschiedener Tracht, mit gegenständigen oder abwechselnden, einfachen, oft rosettenförmig gehäuften, fleischig saftigen Blättern, purpurroten oder hochgelben Blüten …   Meyers Großes Konversations-Lexikon

  • Cotyledon — Cotylĕdon L., Nabelkraut, Pflanzengattg. der Krassulazeen, schönblühende Kapsträucher; bei uns Zierpflanzen …   Kleines Konversations-Lexikon

  • Cotyledon —   [griechisch kotylēdo̅n »Vertiefung«, »Saugwarze«], Kotyledon, Botanik: Gattung der Dickblattgewächse mit etwa 50 meist in Südafrika beheimateten Arten von strauchiger oder stammsukkulenter Wuchsform; zum Teil Zimmerpflanzen.   …   Universal-Lexikon

  • cotylédon — COTYLÉDON, ou Nomeril de Vénus. s. m. Plante qui croît sur les rochers et sur les vieilles murailles. On lui attribue les mêmes vertus qu à la Rhubarbe …   Dictionnaire de l'Académie Française 1798

  • cotyledon — ► NOUN ▪ an embryonic leaf, the first leaf to grow from a germinating seed. ORIGIN Greek kotul d n cup shaped cavity …   English terms dictionary


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