stonewort

stonewort
/stohn"werrt', -wawrt'/, n.
any of a plantlike group of green algae constituting the class Charophyceae, having a jointed body frequently encrusted with lime and usually attached to the bottom in fresh water.
[1575-85; STONE + WORT2]

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      any of certain green algae of the class Charophyceae. Most stoneworts generally occur in fresh water. Some are calcified (Chara) and may accumulate as calcium carbonate deposits. These deposits may be so extensive that they form the major part of the calcareous marl of lakes and are sometimes a detrimental weed in fish hatcheries. Superficially resembling the structures of some higher plants, stonewort structures include rootlike rhizoids, whorls of branches at regular intervals, and an erect cylindrical axis, which may be surrounded by a sheath of small cells. In sexual reproduction each female sex organ (oogonium) contains one large, immobile egg, and each male sex organ (antheridium) produces one small, biflagellate sperm. An envelope of sterile cells surrounds the reproductive structures. No motile spores are formed.

      They are submerged and attached to the muddy bottoms of fresh or brackish rivers and lakes. Stoneworts are of little importance to humans.

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Universalium. 2010.

Look at other dictionaries:

  • Stonewort — Stone wort , n. (Bot.) Any plant of the genus Chara; so called because they are often incrusted with carbonate of lime. See {Chara}. [1913 Webster] …   The Collaborative International Dictionary of English

  • stonewort — [stōn′wʉrt΄] n. any of a class (Charophyceae) of green algae with jointed axes and whorled branches, usually covered with lime …   English World dictionary

  • stonewort — noun Date: 1816 any of various freshwater green algae (order Charales) that have a thallus differentiated into rhizoids and stems with whorls of branchlets and that are often encrusted with calcareous deposits …   New Collegiate Dictionary

  • stonewort — noun Any of various complex algae of the family Characeae, known for being branched and having enclosed egg cells …   Wiktionary

  • stonewort — noun a freshwater plant related to green algae, with whorls of slender leaves sometimes encrusted with chalky deposits. [Chara and other genera.] …   English new terms dictionary

  • stonewort — stone•wort [[t]ˈstoʊnˌwɜrt, ˌwɔrt[/t]] n. pln any of a group of freshwater green algae, of the class Charophyceae, with plantlike growth • Etymology: 1575–85 …   From formal English to slang

  • stonewort — /ˈstoʊnwɜt/ (say stohnwert) noun a green alga of the class Charophyceae, having a jointed plant body frequently encrusted with lime and usually growing in fresh water. {stone + wort2} …   Australian-English dictionary

  • stonewort — n. 1 = stone parsley. 2 any plant of the genus Chara, with a calcareous deposit on the stem …   Useful english dictionary

  • Chara hispida — Gyrogonite Gy*rog o*nite (j[i^]*r[o^]g [ o]*n[imac]t), n. [Gr. gy^ros circle, ring + go nos fruit.] (Paleon.) The petrified fruit of the {Chara hispida}, a species of stonewort. See {Stonewort}. Lyell. [1913 Webster] …   The Collaborative International Dictionary of English

  • Gyrogonite — Gy*rog o*nite (j[i^]*r[o^]g [ o]*n[imac]t), n. [Gr. gy^ros circle, ring + go nos fruit.] (Paleon.) The petrified fruit of the {Chara hispida}, a species of stonewort. See {Stonewort}. Lyell. [1913 Webster] …   The Collaborative International Dictionary of English

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