Root hair

Root hair
Root Root, n. [Icel. r[=o]t (for vr[=o]t); akin to E. wort, and perhaps to root to turn up the earth. See {Wort}.] 1. (Bot.) (a) The underground portion of a plant, whether a true root or a tuber, a bulb or rootstock, as in the potato, the onion, or the sweet flag. (b) The descending, and commonly branching, axis of a plant, increasing in length by growth at its extremity only, not divided into joints, leafless and without buds, and having for its offices to fix the plant in the earth, to supply it with moisture and soluble matters, and sometimes to serve as a reservoir of nutriment for future growth. A true root, however, may never reach the ground, but may be attached to a wall, etc., as in the ivy, or may hang loosely in the air, as in some epiphytic orchids. [1913 Webster]

2. An edible or esculent root, especially of such plants as produce a single root, as the beet, carrot, etc.; as, the root crop. [1913 Webster]

3. That which resembles a root in position or function, esp. as a source of nourishment or support; that from which anything proceeds as if by growth or development; as, the root of a tooth, a nail, a cancer, and the like. Specifically: (a) An ancestor or progenitor; and hence, an early race; a stem. [1913 Webster]

They were the roots out of which sprang two distinct people. --Locke. [1913 Webster] (b) A primitive form of speech; one of the earliest terms employed in language; a word from which other words are formed; a radix, or radical. (c) The cause or occasion by which anything is brought about; the source. ``She herself . . . is root of bounty.'' --Chaucer. [1913 Webster]

The love of money is a root of all kinds of evil. --1 Tim. vi. 10 (rev. Ver.) [1913 Webster] (d) (Math.) That factor of a quantity which when multiplied into itself will produce that quantity; thus, 3 is a root of 9, because 3 multiplied into itself produces 9; 3 is the cube root of 27. (e) (Mus.) The fundamental tone of any chord; the tone from whose harmonics, or overtones, a chord is composed. --Busby. [1913 Webster] (f) The lowest place, position, or part. ``Deep to the roots of hell.'' --Milton. ``The roots of the mountains.'' --Southey. [1913 Webster]

4. (Astrol.) The time which to reckon in making calculations. [1913 Webster]

When a root is of a birth yknowe [known]. --Chaucer. [1913 Webster]

{A["e]rial roots}. (Bot.) (a) Small roots emitted from the stem of a plant in the open air, which, attaching themselves to the bark of trees, etc., serve to support the plant. (b) Large roots growing from the stem, etc., which descend and establish themselves in the soil. See Illust. of {Mangrove}.

{Multiple primary root} (Bot.), a name given to the numerous roots emitted from the radicle in many plants, as the squash.

{Primary root} (Bot.), the central, first-formed, main root, from which the rootlets are given off.

{Root and branch}, every part; wholly; completely; as, to destroy an error root and branch.

{Root-and-branch men}, radical reformers; -- a designation applied to the English Independents (1641). See Citation under {Radical}, n., 2.

{Root barnacle} (Zo["o]l.), one of the Rhizocephala.

{Root hair} (Bot.), one of the slender, hairlike fibers found on the surface of fresh roots. They are prolongations of the superficial cells of the root into minute tubes. --Gray.

{Root leaf} (Bot.), a radical leaf. See {Radical}, a., 3 (b) .

{Root louse} (Zo["o]l.), any plant louse, or aphid, which lives on the roots of plants, as the Phylloxera of the grapevine. See {Phylloxera}.

{Root of an equation} (Alg.), that value which, substituted for the unknown quantity in an equation, satisfies the equation.

{Root of a nail} (Anat.), the part of a nail which is covered by the skin.

{Root of a tooth} (Anat.), the part of a tooth contained in the socket and consisting of one or more fangs.

{Secondary roots} (Bot.), roots emitted from any part of the plant above the radicle.

{To strike root}, {To take root}, to send forth roots; to become fixed in the earth, etc., by a root; hence, in general, to become planted, fixed, or established; to increase and spread; as, an opinion takes root. ``The bended twigs take root.'' --Milton. [1913 Webster]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • root hair — root′ hair n. bot an elongated tubular extension of an epidermal cell of a root, serving to absorb water and minerals from the soil • Etymology: 1855–60 …   From formal English to slang

  • root hair — n. Bot. any of the thin walled, hairlike tubular outgrowths from a growing root, which serve to absorb water and minerals from the soil …   English World dictionary

  • root hair — noun thin hairlike outgrowth of an epidermal cell just behind the tip; absorbs nutrients from the soil • Hypernyms: ↑plant organ • Part Holonyms: ↑root * * * noun : one of the many hairlike tubular outgrowths of epidermal or sometimes cortical… …   Useful english dictionary

  • Root hair — A root hair is a tubular outgrowth of root epidermal cells of vascular plants. They are found only in the region of maturation of the root. Root hairs are a specialized form of rhizoid.Root hairs form an important surface over which plants absorb …   Wikipedia

  • root hair — rizoidai statusas T sritis ekologija ir aplinkotyra apibrėžtis Samanų, kerpių, dumblių, grybų panašios į šaknis išaugos, kuriomis šie augalai prisitvirtina prie substrato, pasisavina iš jo vandenį ir mineralines medžiagas. atitikmenys: angl.… …   Ekologijos terminų aiškinamasis žodynas

  • root hair — /ˈrut hɛə/ (say rooht hair) noun an elongated tubular extension of an epidermal cell of the root serving to absorb water and minerals from the soil …   Australian English dictionary

  • root hair — an elongated tubular extension of an epidermal cell of a root, serving to absorb water and minerals from the soil. [1855 60] * * * …   Universalium

  • root hair — noun Date: 1853 a filamentous extension of an epidermal cell near the tip of a rootlet that functions in absorption of water and minerals …   New Collegiate Dictionary

  • root hair cell — Root epidermal cell, part of which projects from the root surface as a thin tube, thus increasing the root surface area and promoting absorption of water and ions …   Dictionary of molecular biology

  • Root hairs — Root hair cells, the rhizoids of many vascular plants, are tubular outgrowths of trichoblasts, the hair forming cells on the epidermis of a plant root. That is, root hair cells are lateral extensions of a single cell and only rarely branched.… …   Wikipedia

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