根出叶

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.

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

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.

They were the roots out of which sprang two
distinct people. --Locke.
(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.

The love of money is a root of all kinds of
evil. --1 Tim. vi.
10 (rev. Ver.)
(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.
(f) The lowest place, position, or part. ``Deep to the
roots of hell.'' --Milton. ``The roots of the
mountains.'' --Southey.

4. (Astrol.) The time which to reckon in making calculations.

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

{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.