root

part of a plant normally below the ground; basic cause, source, or origin: the root of the problem
Not to be confused with:route – a way or course taken: the shortest route to your destination; a round traveled in delivering, selling, or collecting goods: a newspaper route

root¹

R0301400 (ro͞ot, ro͝ot)n.1. a. The usually underground portion of a plant that lacks buds, leaves, or nodes and serves as support, draws minerals and water from the surrounding soil, and sometimes stores food.b. Any of various other underground plant parts, especially an underground stem such as a rhizome, corm, or tuber.2. a. The embedded part of an organ or structure such as a hair, tooth, or nerve, that serves as a base or support.b. The bottom or supporting part of something: We snipped the wires at the roots.3. The essential part or element; the basic core: I finally got to the root of the problem.4. A primary source; an origin. See Synonyms at origin.5. A progenitor or ancestor from which a person or family is descended.6. a. often roots The condition of being settled and of belonging to a particular place or society: Our roots in this town go back a long way.b. roots The state of having or establishing an indigenous relationship with or a personal affinity for a particular culture, society, or environment: music with unmistakable African roots.7. Linguistics a. The element that carries the main component of meaning in a word and provides the basis from which a word is derived by adding affixes or inflectional endings or by phonetic change.b. Such an element reconstructed for a protolanguage. Also called radical.8. Mathematics a. A number that when multiplied by itself an indicated number of times forms a product equal to a specified number. For example, a fourth root of 4 is √2. Also called nth root.b. A number that reduces a polynomial equation in one variable to an identity when it is substituted for the variable.c. A number at which a polynomial has the value zero.9. Music a. The note from which a chord is built.b. Such a note occurring as the lowest note of a triad or other chord.v. root·ed, root·ing, roots v.intr.1. To grow roots or a root: Carrot tops will root in water.2. To become firmly established or settled: The idea of tolerance has rooted in our culture.v.tr.1. To plant and fix the roots of (a plant) in soil or the ground.2. To establish or settle firmly: Our love of the ocean has rooted us here.3. To be the source or origin of: "Much of [the team's] success was rooted in the bullpen" (Dan Shaughnessy).4. a. To dig or pull out by the roots. Often used with up or out: We rooted out the tree stumps with a tractor.b. To remove or get rid of. Often used with out: "declared that waste and fraud will be vigorously rooted out of Government" (New York Times).Idiom: root and branch Utterly; completely: The organization has been transformed root and branch by its new leaders.

[Middle English rot, from Old English rōt, from Old Norse; see wrād- in Indo-European roots.]

root′er n.

root²

R0301400 (ro͞ot, ro͝ot)v. root·ed, root·ing, roots v.tr.1. To turn up by digging with the snout or nose: hogs that rooted up acorns.2. To cause to appear or be known. Used with out: an investigation that rooted out the source of the problem.v.intr.1. To turn over the earth with the snout or nose.2. To search or rummage for something: rooted around for a pencil in his cluttered office.

[Middle English wroten, from Old English wrōtan.]

root′er n.

root³

R0301400 (ro͞ot, ro͝ot)intr.v. root·ed, root·ing, roots 1. To give audible encouragement or applause to a contestant or team; cheer. See Synonyms at applaud.2. To give moral support to someone; hope for a favorable outcome for someone: We'll be rooting for you when you take the exam.

[Possibly alteration of rout.]

root′er n.

root

(ruːt) n1. (Botany) a. the organ of a higher plant that anchors the rest of the plant in the ground, absorbs water and mineral salts from the soil, and does not bear leaves or budsb. (loosely) any of the branches of such an organ2. (Botany) any plant part, such as a rhizome or tuber, that is similar to a root in structure, function, or appearance3. a. the essential, fundamental, or primary part or nature of something: your analysis strikes at the root of the problem. b. (as modifier): the root cause of the problem. 4. (Anatomy) anatomy the embedded portion of a tooth, nail, hair, etc5. origin or derivation, esp as a source of growth, vitality, or existence6. (plural) a person's sense of belonging in a community, place, etc, esp the one in which he was born or brought up7. an ancestor or antecedent8. (Bible) Bible a descendant9. (Linguistics) the form of a word that remains after removal of all affixes; a morpheme with lexical meaning that is not further subdivisible into other morphemes with lexical meaning. Compare stem¹⁹10. (Mathematics) maths a number or quantity that when multiplied by itself a certain number of times equals a given number or quantity: 3 is a cube root of 27. 11. (Mathematics) maths Also called: solution a number that when substituted for the variable satisfies a given equation: 2 is a root of x³ – 2x – 4 = 0. 12. (Music, other) music (in harmony) the note forming the foundation of a chord13. slang Austral and NZ sexual intercourse14. root and branch a. (adverb) entirely; completely; utterlyb. (adjective) thorough; radical; completevb15. (Botany) (intr) Also: take root to put forth or establish a root and begin to grow16. (intr) Also: take root to become established, embedded, or effective17. (tr) to fix or embed with or as if with a root or roots18. slang Austral and NZ to have sexual intercourse (with)[Old English rōt, from Old Norse; related to Old English wyrt wort] ˈrooter n ˈrootˌlike adj ˈrooty adj ˈrootiness n

root

(ruːt) vb (intr) 1. (Zoology) (of a pig) to burrow in or dig up the earth in search of food, using the snout2. informal (foll by: about, around, in, etc) to search vigorously but unsystematically[C16: changed (through influence of root¹) from earlier wroot, from Old English wrōtan; related to Old English wrōt snout, Middle Dutch wrōte mole] ˈrooter n

root

vb (General Sporting Terms) informal (usually foll by: for) to give support to (a contestant, team, etc), as by cheering [C19: perhaps a variant of Scottish rout to make a loud noise, from Old Norse rauta to roar] ˈrooter n

root¹

(rut, rʊt)

n. 1. a part of the body of a plant that develops, typically, from the radicle and grows downward into the soil, anchoring the plant and absorbing nutriment and moisture. 2. any underground part of a plant, as a rhizome. 3. something resembling or suggesting the root of a plant in position or function. 4. the embedded or basal portion of a hair, tooth, nail, nerve, etc. 5. the fundamental or essential part. 6. the source or origin of a thing: the root of all evil. 7. a person or family as the source of offspring or descendants. 8. roots, a. a person's original or ancestral home, environment, and culture. b. the personal relationships, affinity for a place, habits, etc., that make a locale one's true home. 9. a. a quantity that, when multiplied by itself a certain number of times, produces a given quantity: 2 is the square root of 4, the cube root of 8, and the fourth root of 16. b. r th root, the quantity raised to the power 1/r: 2 is the ? root of 8. c. a value of the argument of a function for which the function takes the value zero. 10. a. a morpheme that underlies an inflectional or derivational paradigm, as dance, the root in danced, dancer or tend-, the root of Latin tendere “to stretch.” b. such a form reconstructed for a parent language, as *sed-, the hypothetical proto-Indo-European root meaning “sit.” 11. a. the fundamental tone of a compound musical tone of a series of harmonies. b. the lowest tone of a chord when arranged as a series of thirds; fundamental. 12. a. (in a screw or other threaded object) the narrow inner surface between threads. b. (in a gear) the narrow inner surface between teeth. v.i. 13. to become fixed or established. v.t. 14. to fix by or as if by roots: We were rooted to the spot in amazement. 15. to implant or establish deeply. 16. to pull, tear, or dig up by the roots (often fol. by up or out). 17. to extirpate; remove completely (often fol. by up or out): to root out crime. Idioms: take root, a. to send out roots; begin to grow. b. to become established. [before 1150; Middle English; late Old English rōt < Old Norse rōt, akin to Old English wyrt plant, wort²]

root²

(rut, rʊt)

v.i. 1. to turn up the soil with the snout, as swine. 2. to poke or search: to root around in a drawer for a cuff link. v.t. 3. to turn over with the snout (often fol. by up). 4. to unearth (often fol. by up). [1530–40; variant of wroot (now obsolete), Middle English wroten, Old English wrōtan, c. Old High German ruozzen; akin to Old English wrōt a snout]

root³

(rut or, sometimes, rʊt)

v.i. 1. to encourage a team or contestant by cheering or applauding enthusiastically. 2. to lend moral support. [1885–90, Amer.; perhaps variant of rout³] root′er, n.

Root

(rut)

n. Elihu, 1845–1937, U.S. statesman: Nobel peace prize 1912.

root

(ro͞ot)1. A plant part that usually grows underground, secures the plant in place, absorbs minerals and water, and stores food manufactured by leaves and other plant parts. In certain plants, additional roots grow out from the stem above ground, bending down into the soil, to provide more support.2. Any of various other plant parts that grow underground, especially an underground stem such as a corm, rhizome, or tuber.3. The part of a tooth that is embedded in the jaw and not covered by enamel.4. Mathematics a. A number that, when multiplied by itself a given number of times, produces a specified number. For example, since 2 × 2 × 2 × 2 = 16, 2 is a fourth root of 16.b. A solution to an equation. For example, a root of the equation x² - 4 = 0 is 2, since 2² - 4 = 0.

root

Past participle: rooted
Gerund: rooting

Imperative
root
root

Present
I root
you root
he/she/it roots
we root
you root
they root

Preterite
I rooted
you rooted
he/she/it rooted
we rooted
you rooted
they rooted

Present Continuous
I am rooting
you are rooting
he/she/it is rooting
we are rooting
you are rooting
they are rooting

Present Perfect
I have rooted
you have rooted
he/she/it has rooted
we have rooted
you have rooted
they have rooted

Past Continuous
I was rooting
you were rooting
he/she/it was rooting
we were rooting
you were rooting
they were rooting

Past Perfect
I had rooted
you had rooted
he/she/it had rooted
we had rooted
you had rooted
they had rooted

Future
I will root
you will root
he/she/it will root
we will root
you will root
they will root

Future Perfect
I will have rooted
you will have rooted
he/she/it will have rooted
we will have rooted
you will have rooted
they will have rooted

Future Continuous
I will be rooting
you will be rooting
he/she/it will be rooting
we will be rooting
you will be rooting
they will be rooting

Present Perfect Continuous
I have been rooting
you have been rooting
he/she/it has been rooting
we have been rooting
you have been rooting
they have been rooting

Future Perfect Continuous
I will have been rooting
you will have been rooting
he/she/it will have been rooting
we will have been rooting
you will have been rooting
they will have been rooting

Past Perfect Continuous
I had been rooting
you had been rooting
he/she/it had been rooting
we had been rooting
you had been rooting
they had been rooting

Conditional
I would root
you would root
he/she/it would root
we would root
you would root
they would root

Past Conditional
I would have rooted
you would have rooted
he/she/it would have rooted
we would have rooted
you would have rooted
they would have rooted

Thesaurus

Noun	1.	root - (botany) the usually underground organ that lacks buds or leaves or nodes; absorbs water and mineral salts; usually it anchors the plant to the groundphytology, botany - the branch of biology that studies plantscalamus - the aromatic root of the sweet flag used medicinallycocoyam, dasheen, eddo, taro - edible starchy tuberous root of taro plantsginseng - aromatic root of ginseng plantshorseradish, horseradish root - the root of the horseradish plant; it is grated or ground and used for seasoningradish - pungent edible root of any of various cultivated radish plantschicory, chicory root - the dried root of the chicory plant: used as a coffee substituteoyster plant, salsify - edible root of the salsify plantHottentot bread, Hottentot's bread - thick edible rootstock of elephant's-footbriarroot - hard woody root of the briar Erica arboreaorrisroot, orris - fragrant rootstock of various irises especially Florentine iris; used in perfumes and medicinessarsaparilla root - dried root of any of various plants of the genus Smilax used as a flavoring agentlicorice root - root of licorice used in flavoring e.g. candy and liqueurs and medicinessenega - dried root of two plants of the genus Polygala containing an irritating saponinmandrake, mandrake root - the root of the mandrake plant; used medicinally or as a narcoticcassava, manioc - cassava root eaten as a staple food after drying and leaching; source of tapiocacarrot - deep orange edible root of the cultivated carrot plantparsnip - the whitish root of cultivated parsnipplant organ - a functional and structural unit of a plant or fungusparenchyma - the primary tissue of higher plants composed of thin-walled cells that remain capable of cell division even when mature; constitutes the greater part of leaves, roots, the pulp of fruits, and the pith of stemsroot system, rootage - a developed system of rootspneumatophore - an air-filled root (submerged or exposed) that can function as a respiratory organ of a marsh or swamp planttaproot - (botany) main root of a plant growing straight downward from the stemadventitious root - root growing in an unusual location e.g. from a stemroot cap - thimble-shaped mass of cells covering and protecting the growing tip of a rootrootlet - small root or division of a rootroot hair - thin hairlike outgrowth of an epidermal cell just behind the tip; absorbs nutrients from the soilprop root - a root that grows from and supports the stem above the ground in plants such as mangrovesbark - tough protective covering of the woody stems and roots of trees and other woody plants
	2.	root - the place where something begins, where it springs into being; "the Italian beginning of the Renaissance"; "Jupiter was the origin of the radiation"; "Pittsburgh is the source of the Ohio River"; "communism's Russian root"origin, source, rootage, beginningderivation - the source or origin from which something derives (i.e. comes or issues); "he prefers shoes of Italian derivation"; "music of Turkish derivation"spring - a point at which water issues forthheadspring, fountainhead, head - the source of water from which a stream arises; "they tracked him back toward the head of the stream"headwater - the source of a river; "the headwaters of the Nile"wellhead, wellspring - the source of water for a welljumping-off place, point of departure - a place from which an enterprise or expedition is launched; "one day when I was at a suitable jumping-off place I decided to see if I could find him"; "my point of departure was San Francisco"place of origin, provenance, provenience, birthplace, cradle - where something originated or was nurtured in its early existence; "the birthplace of civilization"home - place where something began and flourished; "the United States is the home of basketball"point source - a concentrated source (especially of radiation or pollution) that is spatially constrictedtrail head, trailhead - the beginning of a trailpoint - the precise location of something; a spatially limited location; "she walked to a point where she could survey the whole street"
	3.	root - (linguistics) the form of a word after all affixes are removed; "thematic vowels are part of the stem"root word, stem, theme, radical, baselinguistics - the scientific study of languagedescriptor, form, signifier, word form - the phonological or orthographic sound or appearance of a word that can be used to describe or identify something; "the inflected forms of a word can be represented by a stem and a list of inflections to be attached"
	4.	root - a number that, when multiplied by itself some number of times, equals a given numbernumber - a concept of quantity involving zero and units; "every number has a unique position in the sequence"square root - a number that when multiplied by itself equals a given numbercube root - a number that when multiplied three times equals a given number
	5.	root - the set of values that give a true statement when substituted into an equationsolutionset - (mathematics) an abstract collection of numbers or symbols; "the set of prime numbers is infinite"
	6.	root - someone from whom you are descended (but usually more remote than a grandparent)ancestor, antecedent, ascendant, ascendentancestress - a woman ancestorforbear, forebear - a person from whom you are descendedforefather, sire, father - the founder of a family; "keep the faith of our forefathers"foremother - a woman ancestorprimogenitor, progenitor - an ancestor in the direct linerelative, relation - a person related by blood or marriage; "police are searching for relatives of the deceased"; "he has distant relations back in New Jersey"
	7.	root - a simple form inferred as the common basis from which related words in several languages can be derived by linguistic processesetymondescriptor, form, signifier, word form - the phonological or orthographic sound or appearance of a word that can be used to describe or identify something; "the inflected forms of a word can be represented by a stem and a list of inflections to be attached"
	8.	root - the part of a tooth that is embedded in the jaw and serves as supporttooth rootanatomical structure, bodily structure, body structure, complex body part, structure - a particular complex anatomical part of a living thing; "he has good bone structure"tooth - hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defensecementum, cement - a specialized bony substance covering the root of a tooth
Verb	1.	root - take root and begin to grow; "this plant roots quickly"grow - become larger, greater, or bigger; expand or gain; "The problem grew too large for me"; "Her business grew fast"root - cause to take roots
	2.	root - come into existence, originate; "The problem roots in her depression"become - come into existence; "What becomes has duration"
	3.	root - plant by the rootsplant, set - put or set (seeds, seedlings, or plants) into the ground; "Let's plant flowers in the garden"
	4.	root - dig with the snout; "the pig was rooting for truffles"rootle, routcut into, delve, dig, turn over - turn up, loosen, or remove earth; "Dig we must"; "turn over the soil for aeration"
	5.	root - become settled or established and stable in one's residence or life style; "He finally settled down"steady down, take root, settle down, settlestabilise, stabilize - become stable or more stable; "The economy stabilized"roost - settle down or stay, as if on a roost
	6.	root - cause to take rootsgrow - cause to grow or develop; "He grows vegetables in his backyard"root - take root and begin to grow; "this plant roots quickly"

root

¹noun1. stem, tuber, rhizome, radix, radicle the twisted roots of an apple tree2. source, cause, heart, bottom, beginnings, base, seat, occasion, seed, foundation, origin, core, fundamental, essence, nucleus, starting point, germ, crux, nub, derivation, fountainhead, mainspring We got to the root of the problem.plural noun1. sense of belonging, origins, heritage, birthplace, home, family, cradle I am proud of my Brazilian roots.put down roots settle, set up home, get established, make your home, establish yourself They put down roots in India.root and branch1. complete, total, entire, radical, utter, thorough in need of root and branch reform2. completely, finally, totally, entirely, radically, thoroughly, wholly, utterly, without exception, to the last man They want to deal with the problem root and branch.root for someone support, back, encourage, defend, side with, stand up for, stand behind, stick up for (informal), be a source of strength to We'll be rooting for you.root something or someone out1. get rid of, remove, destroy, eliminate, abolish, cut out, erase, eradicate, do away with, uproot, weed out, efface, exterminate, extirpate, wipe from the face of the earth The generals have to root out traitors.2. discover, find, expose, turn up, uncover, unearth, bring to light, ferret out It shouldn't take long to root out the cause of the problem.take root1. take hold, take, develop, establish, become established, become fixed Time is needed for democracy to take root.2. germinate, take, establish, become established, begin to sprout Cover the bulbs with chicken wire, removing it when they take root.Related words
adjective radical

root

²verb dig, hunt, nose, poke, burrow, delve, ferret, pry, rummage, forage, rootle She rooted through the bag.

root¹

noun1. The most central and material part:core, essence, gist, heart, kernel, marrow, meat, nub, pith, quintessence, soul, spirit, stuff, substance.Law: gravamen.2. A fundamental principle or underlying concept:base, basis, cornerstone, foundation, fundament, fundamental, rudiment (often used in plural).3. A point of origination:beginning, derivation, fount, fountain, fountainhead, mother, origin, parent, provenance, provenience, rootstock, source, spring, well.4. A point of origin from which ideas or influences, for example, originate:bottom, center, core, focus, heart, hub, quick.5. The main part of a word to which affixes are attached:base, stem, theme.verb1. To implant so deeply as to make change nearly impossible:embed, entrench, fasten, fix, infix, ingrain, lodge.2. To provide a basis for:base, build, establish, found, ground, predicate, rest, underpin.3. To destroy all traces of.Out or up:abolish, annihilate, blot out, clear, eradicate, erase, exterminate, extinguish, extirpate, kill, liquidate, obliterate, remove, rub out, snuff out, stamp out, uproot, wipe out.Idioms: do away with, make an end of, put an end to.

root²

verbTo express approval, especially by clapping:applaud, cheer, clap.Idiom: give someone a hand.

Translations

使...生根发根根根源根茎

root¹

(ruːt) noun1. the part of a plant that grows under the ground and draws food and water from the soil. Trees often have deep roots; Carrots and turnips are edible roots.根茎2. the base of something growing in the body. the roots of one's hair/teeth. 牙根、（发）根 3. cause; origin. Love of money is the root of all evil; We must get at the root of the trouble.根源4. (in plural) family origins. Our roots are in Scotland.祖先 verb to (make something) grow roots. These plants aren't rooting very well; He rooted the plants in compost.使...生根root beer a kind of non-alcoholic drink made from the roots of certain plants. 植物根茎制成的一种啤酒根汁汽水（用植物的根制成，不含酒精） root crop plants with roots that are grown for food. The farm has three fields of root crops.供食用的块根作物root out1. to pull up or tear out by the roots. The gardener began to root out the weeds.连根拔出2. to get rid of completely. We must do our best to root out poverty.根除take root to grow firmly; to become established. The plants soon took root.生根

root²

(ruːt) verb1. to poke about in the ground. The pigs were rooting about for food.翻弄2. to search by turning things over etc. She rooted about in the cupboard.翻找

root

→ 根zhCN

root

root,

in botany, the descending axis of a plant, as contrasted with the stem, the ascending axis. In most plants the root is underground, but in epiphytesepiphyte
or air plant,
any plant that does not normally root in the soil but grows upon another living plant while remaining independent of it except for support (thus differing from a parasite).
..... Click the link for more information. the roots grow in the air and in hydrophytes (e.g., cattails and water lilies) they grow in water or marshes. Roots function to absorb water and dissolved minerals from the soil, to anchor the plant, and often to store food. There are two main types of root system: the tap-root system, in which there is a main primary root larger than the other branching roots; and the diffuse (or fibrous) root system, in which there are many slender roots with numerous smaller root branches. Tap roots are characteristic of most trees and of many other plants, including the carrot, parsnip, radish, beet, and dandelion. The grasses (e.g., corn, rye, and alfalfa) have diffuse roots; in the sweet potato some of the larger fibrous roots swell to store food—although these should not be confused with the tuber of the Irish potato, which is a modified underground stemstem,
supporting structure of a plant, serving also to conduct and to store food materials. The stems of herbaceous and of woody plants differ: those of herbaceous plants are usually green and pliant and are covered by a thin epidermis instead of by the bark of woody plants.
..... Click the link for more information. . Root systems often far exceed in mass the aboveground portions of the plant: alfalfa roots sometimes reach 40 ft (12 m) in length, and the combined length of all the roots of a mature rye plant has been measured at 380 mi (612 km). These ramified root systems are important agents in preventing soil erosion. Roots grow primarily in length; only the older roots may develop a cambium layer that increases their diameter. Protecting the constantly growing tip of the root is a cap of cells that break off as the root probes through the soil; they are replaced by new cells from a layer of meristematic tissue just behind them. In the center of the root the cells formed earlier by the embryonic cells of this layer differentiate into storage tissue and xylem and phloem vessels to conduct sapsap,
fluid in plants consisting of water and dissolved substances. Cell sap refers to this fluid present in the large vacuole, or cell cavity, that occupies most of the central portion of mature plant cells.
..... Click the link for more information. upward to the leaves and back down to nourish the root cells. On the surface of the epidermis of the growing portion of the root, tiny cellular projections called root hairs extend into the soil to absorb water and minerals. Although root hairs are less than 1-3 in. (.84 cm) long, their great number enables the plant to collect enormous quantities of water, most of which is promptly lost into the air by transpiration. In spite of their slenderness and delicate structure, the spiraling forward thrust of the root tips and the pressure of their expanding cells is sufficient to split solid rock.

root,

in mathematics, number or quantity r for which an equation f(r)=0 holds true, where f is some functionfunction,
in mathematics, a relation f that assigns to each member x of some set X a corresponding member y of some set Y; y is said to be a function of x, usually denoted f(x) (read "f of x ").
..... Click the link for more information. . If f is a polynomialpolynomial,
mathematical expression which is a finite sum, each term being a constant times a product of one or more variables raised to powers. With only one variable the general form of a polynomial is a₀xⁿ+a₁x
..... Click the link for more information. , r is called a root of f; for example, r=3 and r=−4 are roots of the equation x²+x−12=0, because (3)²+(3)−12=0 and (−4)²+(−4)−12=0. In the special case where f(x)=xⁿ−a for some number a, a root of f is called an nth root of a, denoted by ⁿ√a or a^1/n. For example, 2 is the third, or cube, root of 8 (∛8=2), since it satisfies the equation x³−8=0. Every number has n different (real or complex) nth roots; e.g., there are two square roots of 9 (3 and −3) since (3)(3)=9 and (−3)(−3)=9.

Root (botany)

The absorbing and anchoring organ of vascular plants. Roots are simple axial organs that produce lateral roots, and sometimes buds, but bear neither leaves nor flowers. Elongation occurs in the root tip. The older portion of the root, behind the root tip, may thicken through cambial activity. Some roots, grass for example, scarcely thicken, but tree roots can become 4 in. (10 cm) or more in diameter near the stem. Roots may be very long. The longest maple (Acer) roots are usually as long as the tree is tall, but the majority of roots are only a few inches long. The longest roots may live for many years, while small roots may live for only a few weeks or months.

Root tips and the root hairs on their surface take up water and minerals from the soil. They also synthesize amino acids and growth regulators (gibberellins and cytokinins). These materials move up through the woody, basal portion of the root to the stem. The thickened, basal portion of the root anchors the plant in the soil. Thickened roots, such as carrots, can store food that is later used in stem growth. See Cytokinin, Gibberellin

Roots usually grow in soil where: it is not too dense to stop root tip elongation; there is enough water and oxygen for root growth; and temperatures are high enough (above 39^°F or 4^°C) to permit root growth, but not so high that the roots are killed (above 104^°F or 40^°C). In temperate zones most roots are in the uppermost 4 in. (10 cm) of the soil; root numbers decrease so rapidly with increasing depth that few roots are found more than 6 ft (2 m) below the surface. Roots grow deeper in areas where the soil is hot and dry; roots from desert shrubs have been found in mines more than 230 ft (70 m) below the surface. In swamps with high water tables the lack of oxygen restricts roots to the uppermost soil layers. Roots may also grow in the air. Poison ivy vines form many small aerial roots that anchor them to bark or other surfaces.

The primary root originates in the seed as part of the embryo, normally being the first organ to grow. It grows downward into the soil and produces lateral second-order roots that emerge at right angles behind the root tip. Sometimes it persists and thickens to form a taproot. The second-order laterals produce third-order laterals and so on until there are millions of roots in a mature tree root system. In contrast to the primary root, most lateral roots grow horizontally or even upward. In many plants a few horizontal lateral roots thicken more than the primary, so no taproot is present in the mature root system.

Adventitious roots originate from stems or leaves rather than the embryo or other roots. They may form at the base of cut stems, as seen in the horticultural practice of rooting cuttings.

Root

(radix), one of the principal vegetative organs in cormo-phytes (with the exception of mosses), which serves for the attachment of the plant to the substrate, the absorption of water and nutrients from the substrate, the primary conversion of a number of absorbed substances, the synthesis of organic compounds and their subsequent transport to the other plant organs, and the elimination of certain metabolic products. In some plants, the roots have additional functions, such as to serve as a receptacle for reserve materials. In soboliferous plants the roots serve as an organ of vegetative reproduction.

The root is an axial organ of the plant, related in origin to the stem; when the ancestors of terrestrial plants emerged on dry land they developed rhizomelike branches, the prototypes of roots, at the lower end of the sporophyte. Morphologically, the root differs from the stem in the absence of leaves, in the presence of the root cap, and in endogenous branching (the development of lateral roots in the interior parts of the root, or the pericycle).

The typical root is narrow-cylindrical or filamentous. The rudiment of the root already exists in the seed embryo, and when the seed sprouts, it develops into the main root. Acropetalous branching is characteristic (the younger lateral roots and their rudiments arising closer to the crown of the root). Many plants have adventitious roots in addition to the main and lateral roots. Externally, these do not differ from the lateral roots, and they perform the same functions. However, they usually develop on other organs of the plant—the stems, leaves, modified underground and aboveground shoots (bulbs, tubers, rhizomes)—and on older roots. The formation of adventitious roots is the factor that makes for the possibility of vegetative reproduction.

The tip of the root is covered by the root cap, which protects the tip against injury. The root grows in length by means of division of the cells of the apical meristem, in what is called the division zone, and because of significant lengthwise growth in the growth, or expansion, zone (usually 1–2 mm, sometimes to 10 mm). Behind the growth zone is the zone of absorption and differentiation, the outermost layer of which is differentiated into epiblem. The cells of the epiblem form the root hairs, which increase the absorption surface of the root from five to 20 times.

Differentiation of the meristem into the primary permanent tissues begins in the growth zone, but it is manifested distinctly in the absorption zone and in what is called the passage zone. The primary anatomic structure of the roots is similar in all seed plants. Underneath the layer of cells of the epiblem is the mul-tilayered primary cortex, which consists of thin-walled living parenchymal cells. In some plants the walls of the first to third outer layers of cells of the cortex, the exoderm, undergo suberi-zation; upon the atrophy of the epiblem, they assume a protective function. The innermost layer of the primary cortex, or the endoderm, consists of a single layer of cells whose walls are partially suberized or lignified (often thickened); only a few of these cells are unaltered.

Endoderm surrounds the central cylinder, or stele, of the root. One or more of the outer layers of its cells form the pericycle, whose thin-walled, living cells retain their meristematic activity over a long period. The lateral roots and the adventitious buds take form within the pericycle, and the secondary thickening of the root is accomplished with its participation. A large part of the central cylinder is taken up by the complex conducting radial fascicle, in which elements of the xylem and phloem alternate.

In monocotyledonous plants the primary anatomical structure of the root is retained throughout the plant’s life; in dicotyledonous and gymnospermous plants, it is replaced by a secondary structure. In the latter instance, the fascicular cambium deposits (between the xylem and phloem) secondary xylem, or wood, toward the center and secondary phloem, or bast, toward the periphery. The parenchyma of the primary medullary (bast and wood) ray is formed from the interfascicular cambium, located opposite the rays of primary xylem in the pericycle. The cork cambium, or phellogen, deposits cork cells toward the exterior, which becomes the covering tissue of the secondarily thickened root; the entire primary cortex is discarded. These changes cause increases in thickness in the root. A distinction is noted between growth roots, which grow quickly (under favorable circumstances, an average of 1–3 cm per day), thicken, undergo suberi-zation early, constitute the skeleton of the root system, and, in a number of instances, provide for the vegetative propagation of the plant; and suckers, which are thin, delicate, short, slow-growing, and usually short-lived.

All of the roots of a single plant considered together are known as the root system, whose general form and character are determined by the correlation of growth of the main, lateral, and adventitious roots. When the predominant growth is of the main root, a tap-root system is formed (lupine, cotton). When the main root is characterized by weak growth or early atrophy and the predominant development is of a large number of adventitious roots, a fibrous system is formed (monocotyledons; among dicotyledons, species of Ranunculus and Plantago).

The roots of cereal grasses (rye and wheat) penetrate to depths of 1.0-1.5 m; in alfalfa, to 10 m; and in woody plants, to 10–12 m, although hard ground usually impedes penetration deeper than 3–5 m. The area occupied by the root system of a single cereal plant may attain a diameter of 40–60 cm; of melon, 6–8 m; and of woody plants, 10–18 m, exceeding the diameter of the crown by several times. The total length of the roots of annuals may reach several km. The total root surface, including that of the root hairs, exceeds the surface of the aboveground organs by many times.

A distinction is made, according to distribution in the soil (depending on environment), between specialized (superficial or deep) root systems and universal root systems, which develop equally in width and in depth. For example, in the northern forest zone on podzolic soils, which are often oversaturated with moisture, poorly aerated, and have poorly penetrable subsoil, the root systems of plants are 90–95 percent concentrated at the surface layers of the soil (10–15 cm). In semidesert and desert zones, some plants have only surface roots, which take advantage of the precipitation of early spring (ephemera); others use the rains and the condensed moisture that precipitates at the upper layers of the soil at night (cacti); in still others, the roots reach ground waters (camel thorn).

Universal root systems make use of moisture at various levels of the water table at different times; as a result, the plants can grow all summer (Calligonum, Haloxylon, Ephedra). In zones of insufficient moisture there is marked stratification in the root distribution for the various species of plants growing in the same area. The ratio between the roots and the aboveground parts of the plants also depends on the soil and climatic conditions. In the wet northern zone, the mass of the root system is from five to ten times smaller than the mass of the aboveground parts of the plant.

The roots absorb the ions of mineral salts from the soil primarily, but also certain products of the life activities of soil microorganisms and the root excretions of other plants. The compounds of nitrogen, phosphorus, and sulfur absorbed by the roots interact with the products of photosynthesis that flow in from the leaves to form amino acids, nucleotides, and other organic compounds. Elements, in the form of ions (potassium, calcium, magnesium, phosphorus) or organic molecules (nitrogen, sulfur), pass into the leaves and stems along the veins of the xylem as a result of the action of root pressure and transpiration. Alkaloids, such as nicotine, growth hormones (kinins, gibberel-lins), and other physiologically active substances are also synthesized in the roots. In some plants (predominantly of the legume family), bacteria that induce the production of nodules from the root parenchyma inhabit the roots.

The roots discharge into the soil the ions of mineral salts, amino acids, sugar, urea, and phenolic compounds. In some plants, such as those of the nightshade family (Solanaceae) the roots also secrete auxins and substances of the gibberellin family, which stimulate plant growth; in others, they secrete gelatinous substances that form root-protective sheaths. Root secretions foster the development of soil microorganisms in the rhizo-sphere. As the plant grows, the amount of secretion decreases, and with it, the number of rhizosphere microorganisms. The nodular bacteria play an important role in the nitrogen nutrition of the plants and in increasing soil fertility. Mycorrhizae-form-ing fungi inhabit the surface or the interior of the roots of many woody and herbaceous plants, in which root hairs do not develop.

Adventitious buds that yield aerial shoots (in soboliferous plants) form on the roots of many plants. In a number of plants the roots serve as a repository for reserve nutrients (root crops). In certain tropical trees, the lateral or adventitious roots (slablike, stiltlike, or columnar), which serve for support and nutrition, branch off near the base of the trunk or from the limbs. Creeping lianas, such as ivy, develop holdfast roots. In the tropics, many epiphytes form adventitious aerial roots that absorb water from atmospheric precipitation through the multilayered surface of their tissue, called the velamen. In some tropical epiphytic orchids and in plants of the family Podostemaceae, the leaves and stems are underdeveloped; their vegetative organs are represented chiefly by flat green roots that perform the functions of assimilation. Plants living in oxygen-poor soils, such as the marsh cypress and the mangrove, have respiratory roots, or pneumatophores, whose crowns are located above the soil or water and supply the underground organs with air. In some palms and in plants of the family Rubiaceae, some of the horizontal roots are transformed into protective thorns. The roots of plants that parasitize trees, such as the mistletoe, have the appearance of long cylindrical rods distributed in the bark of the tree. In parasitic plants (broom rape, dodder) and semiparasites (cow wheat, yellow rattle), the root system develops poorly; at the same time, the endings of some of the roots embed themselves within the body of the host plant in the form of special suckers, or haustoria, which draw the nutrients from the host. In other plants, such as the hornwort and the bladderwort, roots are absent; this is due to special features of their life conditions.

The roots of many plants are widely used by man and have great nutritional and economic significance. Roots that contain starch, sugar, oils, alkaloids, latex, dyes, and other valuable substances are used in medicine and industry. Plants with highly developed root systems are used for holding shifting sands and eroded soils and for attachment to cliffs.

REFERENCES

Krasovskaia, I. V. “Obzor rabot po morfologii i fiziologii kornei.” Trudy po prikladnoi botanike, genetike i selektsii, 1928, vol. 18, issue 5.
Krasovskaia, I. V. “Zakonomernosti stroeniia kornevoi sistemy khlebnykh zlakov.” Botanicheskii zhurnal, 1950, vol. 35, no. 4.
Shalyt, M. S. “Podzemnaia chast’ nekotorykh lugovykh, stepnykh i pustynnykh rastenii i fitotsenozov.” Trudy Botanicheskogo instituta AN SSSR, series 3. Geobotanika, 1950, issue 6.
Sabinin, D. A. Fiziologicheskie osnovy pitaniia rastenii. Moscow, 1955.
Kachinskii, N. A. Pochva, ee svoistva i zhizn’. Moscow, 1956.
Kolesnikov, V. A. Kornevaia sistema plodovykh i iagodnykh rastenii i metody ee izucheniia. Moscow, 1962.
Fedorov, A. A., M. E. Kirpichnikov, and Z. T. Artiushenko. Atlas po opisatel’noi morfologii vysshikh rastenii, vol. 2. Moscow-Leningrad, 1962.
Kolosov, 1.1. Poglotitel’naia deiatel’nost ‘kornevykh sistem rastenii. Moscow, 1962.
Rakhteenko, I. N. Rost i vzaimodeistvie kornevykh sistem drevesnykh rastenii. Minsk, 1963.
Voronin, N. S. “Evoliutsiia pervichnykh struktur ν korniakh rastenii.”
Uch. zap. Kaluzhskogo pedagogicheskogo instituta, 1964, issue 13.
Boiko, L. A. Fiziologiia kornevoi sistemy rastenii ν usloviiakh zasoleniia. Leningrad, 1969.
Esau, K. Anatomiia rastenii. Moscow, 1969. (Translated from English.)

O. N. CHISTIAKOVA, R. P. BARYKINA, and D. B. VAKHMISTROV

Root

(in linguistics), a morpheme (morph) that is the common element of a group of words derived from it and having a basically common lexical meaning.

Roots are determined by eliminating all inflectional and derivational affixes—for example, Russian luch in the words luch, “ray”; luchi, “rays”; luchevoi, “ray” (adjective); and izluchenie, “radiation.” In some languages the root may undergo sound changes, as in the German find/fand/fund in the words finden, fand, gefunden, “to find,” and the Arabic h-s-b in the words hisā b, “account,” hāsib, “meter,” and muhtasib, “controller of weights and measures.” Compound words may contain two or more roots, as in the Russian luchevidnyi, “raylike” (roots luch + vid).

The etymological root is the form and meaning of a word, conceived as the original—for example, the Russian kol with the meaning of “circle” in the words koleso, “wheel,” and okolo, “around.”

Root

(mathematics). (1) The nth root of a number a is a number x (denoted by whose nth power is equal to a (that is, xⁿ = a). The operation of finding the root is called extraction of a root. When a ≠ 0, there are n different values (generally complex numbers) of the root; for example, the values of are 2, –1 + i, and –1 –i .

Many geometric problems posed by ancient mathematicians reduced to finding roots of numbers. Among Babylonian cuneiform writings (second millennium B.C.) there are descriptions of methods of approximating square roots, as well as tables of square roots. A special symbol is encountered in Egyptian papyri for the extraction of roots. Ancient Greek mathematicians established that the side of a square is not commensurable with its diagonal (equal to a if a is the length of a side), which later led to the discovery of irrational numbers. Aryabhata (fifth century) gave a rule for extracting square and cube roots. Omar Khayyam (second half of the 11th century or beginning of the 12th century), al-Kashi (15th century), and the German mathematician M. Stifel (16th century) extracted higher roots on the basis of the formula for (a + b)ⁿ. L. Euler (18th century) gave approximation methods for extracting roots that have retained their significance. Square roots of negative numbers, encountered in works by J. Cardan and R. Bombelli in the 16th century, led to the discovery of complex numbers.

(2) The root of the algebraic equation

(1) a₀xⁿ + a₁x^n-1 + . . . + a_n-1x + a_n = 0

is a number c that, when substituted for x, reduces the equation to an identity. The root of equation (1) is also called the root of the polynomial

f(x) = a₀xⁿ + a₁x^n-1 + . . . + a_n

If c is the root of the polynomial f(x), then f(x) is divisible without a remainder by x — c.

root

[rüt] (computer science) The origin or most fundamental point of a tree diagram. Also known as base. (botany) The absorbing and anchoring organ of a vascular plant; it bears neither leaves nor flowers and is usually subterranean. (civil engineering) The portion of a dam which penetrates into the ground where the dam joins the hillside. (design engineering) The bottom of a screw thread. (geology) The lower limit of an ore body. Also known as bottom. The part of a fold nappe that was originally linked to its root zone. (mathematics) A root of a given real or complex number is a number which when raised to some exponent equals that number. Also known as radix. A root of a polynomial p (x) is a number a such that p (a) = 0. A root of an equation is a number or quantity that satisfies that equation. (metallurgy) root of weld

root

That portion of a tenon in the plane of the shoulders.

root

1. a. the organ of a higher plant that anchors the rest of the plant in the ground, absorbs water and mineral salts from the soil, and does not bear leaves or buds b. (loosely) any of the branches of such an organ 2. any plant part, such as a rhizome or tuber, that is similar to a root in structure, function, or appearance 3. Anatomy the embedded portion of a tooth, nail, hair, etc. 4. Bible a descendant 5. Maths a number or quantity that when multiplied by itself a certain number of times equals a given number or quantity 6. Maths a number that when substituted for the variable satisfies a given equation 7. Music (in harmony) the note forming the foundation of a chord

root

1. The Unix superuser account (withuser name "root" and user ID 0) that overrides filepermissions. The term avatar is also used. By extension,the privileged system-maintenance login on any operating system.

See root mode, go root, wheel.

root

(1) (verb) To have access to all of the device's resources. See rooting.

(2) (noun) The highest privilege level the user has for accessing resources in the computer. See root level.

(3) The starting point in a structure. See root directory.

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Patient discussion about root

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Synonyms for root

noun stem

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noun source

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noun sense of belonging

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phrase put down roots

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phrase root and branch: complete

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phrase root and branch: completely

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phrase root for someone

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phrase root something or someone out: get rid of

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phrase root something or someone out: discover

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phrase take root: take hold

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phrase take root: germinate

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verb dig

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Synonyms for root

noun the most central and material part

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noun a fundamental principle or underlying concept

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noun a point of origination

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