Kids Research Express

Rye, cereal grain of the family Gramineae (grass family). The grain, Secale cereale, is important chiefly in Central and N Europe. It seems to have been domesticated later than wheat and other staple grains; cultivated rye is quite similar to the wild forms and no traces of it have been found among Egyptian ruins or Swiss lake dwellings. Where it grows well, wheat is preferred, but rye will produce a good crop on soil too poor or in a climate too cool to produce a good crop of wheat. The standard schwarzbrot, or pumpernickel, of Europe was formerly the major rye product. A bread of lighter color, called rye bread, is made of rye flour mixed with wheat flour. Today rye is used mostly as a stock feed (usually mixed with other grains), for hay and pasturage, for green manure, and as a cover crop. Russia leads in world production. Rye is much used as a distillers' grain in making whisky and gin. The tough straw of rye is valued for many purposes, e.g., thatching for roofs and stuffing ...

Shadbush, Juneberry, or serviceberry, any species of the genus Amelanchier of the family Rosaceae (rose family), chiefly North American shrubs or trees conspicuous in the early spring for their white blossoms. The bush is more often called shadbush on the East Coast (it is said to bloom when the shad are running); serviceberry is in general a Western name. The huckleberrylike fruits of native species were eaten by the Native Americans and are still sometimes collected. They are an important wildlife food. Some kinds of shadbush are cultivated for ornament. The wood is very hard. Shadbushes are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

Cinquefoil (sĭngk`foil) [O.Fr.,=five leaves], name for any plant of the widely distributed genus Potentilla of the family Rosaceae (rose family), chiefly herbs of north temperate and subarctic regions. Most cinquefoils are perennial; many but not all of them have leaves of five leaflets, for which they are also called five-finger. The flowers are most often yellow. Most North American species are native to cooler regions of the W United States. The shrubby cinquefoil (P. fruticosa) and the silverweed (P. anserina) are common wildflowers in the West and the Northeast; they are thought to be naturalized from the Old World. These and other species are sometimes cultivated in rock gardens. Silverweed is one of the species reputed to have medicinal powers, hence the Latin name of the genus [potens=powerful]. Cinquefoil is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

Strawberry, any plant of the genus Fragaria of the family Rosaceae (rose family), low herbaceous perennials with edible red fruits, native to temperate and mountainous tropical regions. The European everbearing strawberry (F. vesca) is the only species that does not put out the stolons typical of this easily propagated genus. It has been cultivated sporadically since pre-Christian times but intensively only since the 15th cent. The common strawberry, grown in many varieties in both Europe and America, is Fragaria × Ananassa, the result of the hybridization of F. chiloensis, believed to be indigenous to Chile and to the mountains of W North America, with the wild strawberry (F. virginiana) of E North America. Both species were introduced to Europe by New World explorers; the large French industry grew from a single common strawberry plant. Strawberries are sold fresh, frozen, or in preserves and are used in confectionery and for flavoring. Strawberries are classified in the division Mag...

Bramble, name for plants of the genus Rubus [Lat.,=red, for the color of the juice]. This complex genus of the family Rosaceae (rose family), with representatives in many parts of the world, includes the blackberries, raspberries, loganberries, boysenberries, and dewberries. The plants are typically shrubs with prickly stems (called "canes") and edible fruits that botanically are not berries but aggregates of drupelets (see fruit). The underground parts of brambles are perennial and the canes biennial; only second-year canes bear flowers and fruits. Innumerable horticultural varieties have been bred. The native American black raspberry, or blackcap (R. occidentalis), and red raspberry (R. strigosus) as well as the European red raspberry (R. idaeus) are all cultivated in North America, chiefly in the Northeast. Numerous blackberry species and varieties are cultivated in many regions, particularly in the south central states. Closely resembling the blackberries, except for a mo...

Blackberry, usually prickly, fruit-bearing bush of the genus Rubus, in the rose family, native chiefly to northern temperate regions. The blackberry is abundant in eastern North America and on the Pacific coast; in Europe it is common in thickets and hedges. Its usually biennial, prickly, and erect, semierect, or trailing stems bear leaves with usually three or five oval, coarsely toothed, stalked leaflets; white, pink, or red flowers in terminal clusters; and black or red-purple aggregate fruits. The several trailing species are commonly called dewberries. Blackberries are a fairly good source of iron and vitamin C.

Raspberry, any of many species of fruit-bearing bushes of the genus Rubus in the rose family. When picked, the juicy red, purple, or black berry separates from a core, whereas in the related blackberry the core is part of the fruit. Both so-called berries are actually aggregate fruits. Red raspberries are propagated by suckers from the roots of the parent plant or from root cuttings. Black and purple varieties have arched canes and are propagated by layering of the shoot tips. Raspberries contain iron and vitamin C. They are eaten fresh and are also very popular in jams, as a pastry filling, and as a flavouring for liqueurs.

Quince, shrub or small tree of the Asian genera Chaenomeles and Cydonia of the family Rosaceae (rose family). The common quince (Cydonia oblonga) is a spineless tree with edible fruits cultivated from ancient times in Asia and in the Mediterranean area, where it was early naturalized. Its pome fruit is similar to that of the related apple and pear but is very astringent, and hence it is used chiefly cooked in preserves; marmalade is said to have first been made from quince. As a commercial fruit tree, the quince is cultivated more widely in the temperate zone of Europe than in the United States, where it is grown chiefly in California and New York. It is often used as a rootstock for dwarf fruit trees, especially the pear. The flowering quinces (genus Chaenomeles) are cultivated as ornamental shrubs for their profuse, usually thorny branches and attractive scarlet, pink, or white flowers. The fruit is too small and hard to be of commercial value but is sometimes used locally. Best know...

L oquat (lō`kwŏt), small ornamental evergreen tree (Eriobotrya japonica) and its fruit. It belongs to the family Rosaceae (rose family) and is probably indigenous to China. It has been grown from antiquity in Japan and N India and is cultivated also in Indochina, the Mediterranean region, and to some extent in the New World subtropics. The yellowish, oval fruits are borne in clusters and taste somewhat like apples or pears but are slightly tart. They are commonly eaten fresh but are used also for making jam, jelly, pie, and sauces. Sometimes the loquat is called Japanese medlar, probably because it somewhat resembles the medlar of Europe and Asia. The loquat is one of the few important fruit trees of the tropics belonging to the rose family. Loquat is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

Apricot [Arabic from Lat.,=early ripe], tree, Prunus armeniaca, and its fruit, of the plum genus of the family Rosaceae (rose family), native to temperate Asia and long cultivated in Armenia. The fruit is used raw, canned, preserved, and dried. California is the chief place of cultivation in the United States, although by selecting suitable varieties the apricot can be grown in most regions where the peach is hardy. Apricots are used in the making of a cordial and also for apricot brandy. A number of apricot-plum hybrids, such as the plumcot, Pluot, and Aprium, have been developed. Apricots are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

Cherry, name for several species of trees or shrubs of the genus Prunus (a few are sometimes classed as Padus) of the family Rosaceae (rose family) and for their fruits. The small, round red to black fruits are botanically designated drupes, or stone fruits, as are those of the closely related peach, apricot, and plum. The cherry is one of the most commonly grown home-orchard fruits. About 600 varieties are cultivated, practically all derived from two species—P. avium (sweet cherries) and P. cerasus (sour cherries). Both are believed to be native to Asia Minor and have long been cultivated; they were mentioned in the writings of the ancients. Sour cherries are hardier and more easily grown than sweet cherries and are mostly self-fertile, while many sweet cherries must be cross-pollinated to bear well. The fruit is popular raw, in preserves, and in pies; cherry cider and liqueurs are also made. Europe is the largest producing area. Several species of the flowering cherry, many nati...

Pear, name for a fruit tree of the genus Pyrus of the family Rosaceae (rose family) and for its fruit, a pome. The common pear (P. communis) is one of the earliest cultivated of fruit trees, both in its native W Asia and in Europe. Most of the pear strains grown for their sweet and juicy fruit are varieties of P. communis or of its hybrids with other species of Pyrus—usually P. pyrifolia, known as the Japanese, Chinese, or sand pear and indigenous to China. The main use of the sand pear today is as a rootstock in pear orchards; the related quince is used for the same purpose. Pear strains with fruit of really good eating quality were not developed until the 18th and 19th cent. in N Europe, whence almost all the present successful varieties (e.g., the Bartlett and Seckel) grown in the United States (chiefly on the Pacific coast and in the Great Lakes area) were directly imported. European production is far greater—especially in Germany, France, and Switzerland, where much of the crop i...

Figwort, common name for some members of the Scrophulariaceae, a family comprising chiefly herbs and small shrubs and distributed widely over all continents. The family includes a few climbing types and some parasitic and saprophytic forms. Common Species and Their Uses Among its many wildflowers are several European species that have been introduced to America and become thoroughly naturalized, e.g., the mulleins (genus Verbascum), the common speedwell (Veronica officinalis), and the butter-and-eggs (Linaria vulgaris). The common mullein (V. thapsus), also called flannel plant and torches, was formerly a favorite multipurpose medicinal plant; it is still occasionally used for domestic remedies, e.g., as a tea for coughs. Its large stalks are said to have been oiled and used for funeral torches in early times. The speedwells, of which several species are native to the United States, are also called veronica, supposedly because of a resemblance of the flower to the relic (see veronica...

Rhizome (rī`zōm) or rootstock, fleshy, creeping underground stem by means of which certain plants propagate themselves. Buds that form at the joints produce new shoots. Thus if a rhizome is cut by a cultivating tool it does not die, as would a root, but becomes several plants instead of one, which explains why such weeds as Canada thistle and crabgrass are so hard to eradicate. Ginger, the common iris, trillium, and Solomon's-seal all have rhizomes. True arrowroot is starch from the rhizome of a West Indian plant. See perennial. Tuber , enlarged tip of a rhizome (underground stem) that stores food. Although much modified in structure, the tuber contains all the usual stem parts—bark, wood, pith, nodes, and internodes. The eyes of a potato tuber are nodes where sprouts appear, and they are arranged in the same spiral pattern characteristic of buds on an aerial stem.

Oak, any tree or shrub of the genus Quercus of the family Fagaceae (beech family). This complex genus includes as many as 600, found chiefly in north temperate zones and also in Polynesia. The more southerly species, ranging into the tropics, are usually evergreen. Oaks are cultivated for ornament and are prized as the major source of hardwood lumber. The wood is durable, tough, and attractively grained; it is especially valued in shipbuilding and construction and for flooring, furniture, railroad ties, barrels, tool handles, and veneer (particularly highly burled oak). The oaks are commonly divided into two groups, the black (or red) and the white. The former (e.g., the scarlet, pin, Spanish, willow, laurel, and shingle oaks) are characterized by leaves with sharp-tipped lobes and by acorns that mature in two years. The white oaks (e.g., the white, post, bur, cork, and holly oaks) are characterized by smooth-lobed leaves and acorns that mature in one year. Q. alba, the white oak, is t...

Celery, biennial plant (Apium graveolens) of the family Umbelliferae (parsley family), of wide distribution in the wild state throughout the north temperate Old World and much cultivated also in America. It was first cultivated as a medicinal, then (during the Middle Ages) as a flavoring, and finally as a food, chiefly for soups and salads. The seeds are still used for seasoning. Celeriac is a variety cultivated chiefly in N Europe for the large edible turniplike root. Celery is classified in the division Magnoliophyta, class Magnoliopsida, order Umbellales, family Umbelliferae.

Parsnip, garden plant (Pastinaca sativa) of the family Umbelliferae (parsley family), native to the Old World. It has been cultivated since Roman times for its long, fleshy, edible root. Wine and beer have also been made from it. The wild form has become naturalized in North America, often proving a noxious weed. Parsnip is a biennial but is cultivated as an annual. The root can be left in the ground all winter without deterioration. It is also used as livestock feed. Parsnip is classified in the division Magnoliophyta, class Magnoliopsida, order Apiales, family Umbelliferae.

Carrot, common name for some members of the Umbelliferae, a family (also called the parsley family) of chiefly biennial or perennial herbs of north temperate regions. Most are characterized by aromatic foliage, a dry fruit that splits when mature, and an umbellate inflorescence (a type of flattened flower cluster in which the stems of the small florets arise from the same point, like an umbrella). The seeds or leaves of many of these herbs have been used for centuries for seasoning or as greens (e.g., angelica, anise, caraway, chervil, coriander, cumin, dill, fennel, lovage, and parsley). The carrot, celery, and parsnip are vegetables of commercial importance. The common garden carrot (Daucus carota sativa) is a root crop, probably derived from some variety of the wild carrot (or Queen Anne's lace). In antiquity several types of carrot were grown as medicinals, and in Europe carrots have long been grown for use in soups and stews. The custom of eating carrots raw as a salad has bec...

Watercress, hardy perennial European herb (Nasturtium officinale) of the family Cruciferae (mustard family), widely naturalized in North America, found in or around water. Often cultivated commercially for the small, pungent leaflets, it is used as a peppery salad green or garnish. Other plants of the genus are sometimes called watercress and are used similarly. Watercress was formerly used as a domestic remedy and against scurvy. The ornamental plant whose common name is nasturtium is unrelated. Watercress is classified in the division Magnoliophyta, class Magnoliopsida, order Capparales, family Cruciferae.

Radish, herbaceous plant (Raphanus sativus) belonging to the family Cruciferae (mustard family), with an edible, pungent root sliced in salads or used as a relish. It is thought to be native to China; it spread to the Mediterranean area before Greek times and to the New World in the early 16th cent. There are many varieties, with white, red, or black roots of different shapes and sizes, some quite large. Radishes grow easily and quickly throughout temperate regions; they are a staple food in Japan and China, where they are generally pickled in brine. Radishes are classified in the division Magnoliophyta, class Magnoliopsida, order Capparales, family Cruciferae.

Turnip, garden vegetable of the same genus of the family Cruciferae (mustard family) as the cabbage; native to Europe, where it has been long cultivated. The two principal kinds are the white (Brassica rapa) and the yellow (B. napobrassica), which is known as the rutabaga, the Swedish turnip, or the swede. The rutabaga is grown extensively only in Europe, where it is believed to have originated during the Middle Ages as a cross between the white turnip and the cabbage. The turnip is one of the root crops used as a stock feed as well as for human food. The green leaves (greens) are often cooked like spinach. The turnip is a biennial cool-weather crop, grown mostly in cool climates. The worst turnip pests are the root maggot and the flea beetle; it is also attacked by clubroot fungus. Turnips are classified in the division Magnoliophyta, class Magnoliopsida, order Capparales, family Cruciferae.

Cabbage, leafy garden vegetable of many widely dissimilar varieties, all probably descended from the wild, or sea, cabbage (Brassica oleracea) of the family Cruciferae (mustard family), found on the coasts of Europe. It is used for food for man and stock, mostly in Europe and North America. Well-known varieties of the species include the cabbages, broccoli, Brussels sprouts, cauliflower, collards, kale, and kohlrabi. All grow best in cool, moist climates. They are attacked mostly by insect pests. The true cabbages (var. capitata) include the white and red types and the Savoy type (grown mostly in Europe), with curly, loose leaves. Inexpensive and easily stored, cabbage is important in the diet of many poorer peoples. Popular cabbage dishes include sauerkraut and slaw (raw cabbage). Chinese cabbage, or petsai, chiefly a salad plant, is a separate species (B. pekinensis) grown in many varieties, especially in East Asia. Cabbages with multicolored leaves are becoming popular as ornamenta...

Lavender, common name for any plant of the genus Lavandula, herbs or shrubby plants of the family Labiatae (mint family), most of which are native to the Mediterranean region but naturalized elsewhere. The true lavender (L. officinalis) has grayish foliage and small blue or pale purplish flowers (white in one variety). It is popular for herb gardens and is cultivated commercially or, more commonly, gathered wild for the fragrant flowers, valued for scenting linens and clothes and as the source of oil of lavender. The oil is distilled for use in perfumery, in toilet preparations (e.g., lavender water). Lavender is sometimes used as a flavoring. Spike lavender (L. latifolia), a broader-leaved, less fragrant species, yields spike-lavender oil, which is also used in perfumery and in varnishes and porcelain painting. Lavender is classified in the division Magnoliophyta, class Magnoliopsida, order Lamiales, family Labiatae.

Thyme (tīm), any species of the genus Thymus, aromatic herbs or shrubby plants of the family Labiatae (mint family). The common thyme, which is used as a seasoning herb and yields a medicinal essential oil containing thymol, is the Old World T. vulgaris, an erect plant with grayish branches. It is cultivated mainly in Spain and in France. A compound derived from T. vulgaris, thymine, is used as a topical antifungal. The wild or creeping thyme, or mother-of-thyme (T. serpyllum), also used medicinally, is an Old World evergreen naturalized in North America and popular as a ground cover, edging, and rock plant. This was the wild thyme mentioned in Shakespeare's Midsummer Night's Dream. The Greeks used thyme as a temple incense, and it has been prized since ancient times as a honey plant. Thyme is classified in the division Magnoliophyta, class Magnoliopsida, order Lamiales, family Labiatae.

Weed, common term for any wild plant, particularly an undesired plant, growing in cultivated ground, where it competes with crop plants for soil nutrients and water. In their natural habitat, wildflowers and herbs not only provide beauty but function in many useful ways, e.g., as a source of food for insects and animals and to enrich the earth, loosen hard-packed soils, and help prevent erosion. However, when they invade cultivated areas they often interfere with the desired crop by appropriating space, sunlight, moisture, and soil nutrients. Weeds may also harbor and spread insect and fungus pests. Dried weeds along roadsides are often the starting point for brush and forest fires. Their habits of growth and of propagation must be considered in attempting to eradicate them. Control methods include continual soil cultivation, blanketing the soil with some material (e.g., mulch) to thwart weed growth, and the use of various herbicides (see spraying). Plants which are cultivated in one r...

Garlic, bulbous perennial plant (Allium sativum) of the lily family, native to central Asia and growing wild in Italy and southern France. The bulbs are used as a flavouring. A classic ingredient in many national cuisines, garlic has a powerful onionlike aroma and pungent taste. Since ancient and medieval times it has been prized for its medicinal properties; it was formerly carried as a charm against vampires and other evils. Garlic bulbs are used sliced or crushed to flavour sauces, stews, and salad dressings. The membranous skin of the garlic bulb encloses up to 20 edible bulblets called cloves. See also allium.

Sesame (sĕs`əmē), herb (Sesamum indicum or orientale) cultivated for its seeds since ancient times, found chiefly in the tropics of Africa and Asia. Sesame seeds, also called bennes or gingellies, are black or white and yield an oil that resists turning rancid. The oil (known also as teel oil) is used extensively in India for cooking, soap manufacture, food, and medicine and as an adulterant for olive oil. The seeds are also popularly added to cookies and other baked goods and are made into candy (e.g., benne cakes). Sesame was introduced by African slaves to the U.S. South, where it sometimes becomes a weed. The sesame was once credited with mystic powers. Sesame is classified in the division Magnoliophyta, class Magnoliopsida, order Serophulariales, family Pedaliaceae.

Anise (ăn`ĭs), annual plant (Pimpinella anisum) of the family Umbelliferae (parsley family), native to the Mediterranean region but long cultivated elsewhere for its aromatic and medicinal qualities. It has flat-topped clusters of small yellow or white flowers that become seedlike fruits—the aniseed of commerce, used in food flavoring. Anise oil is derived from the seeds and sometimes from the leaves. The oil, composed chiefly of anethole, is used in medicinals, dentifrices, perfumes, beverages, and, in drag hunting, to scent a trail for dogs in the absence of a fox. The anise of the Bible (Mat. 23.23) is dill, a plant of the same family. Anisette is an anise-flavored liqueur. Star anise (Illicium verum), an unrelated, slow-growing evergreen tree native to SE China and NE Vietnam that can reach 60 ft (18 m) in height. The unripe, anise-flavored, star-shaped fruit of the tree is used whole or ground in Asian cooking as spice and in traditional Asian medicine. A compound extracted from...

Tarragon (târ`əgŏn), perennial aromatic Old World herb (Artemisia dracunculus) of the family Asteraceae (aster family), of the same genus as wormwood and sagebrush. It has long been cultivated in Europe and W Asia for its leaves, used for flavoring vinegar, salads, sauces, soups, and pickles. Its essential oil, sometimes called estragon, is occasionally used in perfume or, in the Old World, medicinally to stimulate appetite or as a diuretic. Tarragon is classified in the division Magnoliophyta, class Magnoliopsida, order Asterales, family Asteraceae.

Sage, any species of the large genus Salvia, aromatic herbs or shrubs of the family Labiatae (mint family). The common sage of herb gardens is S. officinalis, a strongly scented shrubby perennial, native from S Europe to Asia Minor. The dried leaves are used as seasoning, especially in dressings for meat and poultry and also in sage cheese; sage tea, once popular as a beverage, has also been used as a domestic remedy for colds and other ailments and as a hair rinse; the oil is used in medicinals and flavorings and sometimes in perfumery. Prized since ancient times, common sage was thought to prolong life and to increase wisdom by strengthening the memory—whence the name. The ornamental sages are often popularly called salvia. Of these the scarlet sage (S. splendens), native to Brazil, is best known. Clary (S. sclarea), native from the Mediterranean region to Iran, is a biennial sage whose seeds were once used to "clear the eye"; it has bluish or pinkish flowers, and its oil i...

Rosemary [ultimately from Lat.,=dew of the sea], widely cultivated evergreen and shrubby perennial (Rosmarinus officinalis) of the family Labiatae (mint family), fairly hardy and native to the Mediterranean region. It has small light-blue flowers. The aromatic leaves, whitish beneath, are used for seasoning, and the oil is used in perfume and medicine. Rosemary is classified in the division Magnoliophyta, class Magnoliopsida, order Lamiales, family Labiatae.

Bamboo, plant of the family Gramineae (grass family), chiefly of warm or tropical regions, where it is sometimes an extremely important component of the vegetation. It is most abundant in the monsoon area of E Asia. Bamboos are the the largest grasses, sometimes reaching 100 ft (30 m). The stalks are round (rarely square), jointed, sometimes thorny, and hollow or solid with evergreen or deciduous leaves. Some types die after fruiting and some do not flower until they are about 30 years old. In many places bamboo is used as wood for construction work, furniture, utensils, fiber, paper, fuel, and innumerable small articles. Bamboo sprouts are eaten as a vegetable, and the grains of some species are also utilized for food. The bamboo has long been used for decorative purposes, both in gardens and in art. In the United States the native bamboo is a cane. The most common bamboo is Bambusa arundinacea. Bamboo is classified in the division Magnoliophyta, class Lilopsida, order Cyperales, fami...

Sugarcane, tall tropical perennials (species of Saccharum, chiefly S. officinarum) of the family Gramineae (grass family), probably cultivated in their native Asia from prehistoric times. Sugarcane somewhat resembles corn and sorghum, with a large terminal panicle and a noded stalk. In biblical times, one of the known sweetening agents in the world was honey. It was not until the Middle Ages that the "Indian honey-bearing reed" was introduced to the Middle East and became accessible to Europe, where sugar was sold from druggists' shelves as a costly medicinal or luxury. Later, sugarcane plants were introduced by Spanish and Portuguese explorers of the 15th and 16th cent. throughout the Old and New World tropics, and the large cane industry rapidly took shape. Today, sugarcane and the sugar beet (see beet), a temperate plant developed as a commercial sugar source c.1800, are the only two major economic sources of sugar. Cuba and India together produce a large percentage of...

The cotton plant belongs to the genus Gossypium of the family Malvaceae (mallow family). It is generally a shrubby plant having broad three-lobed leaves and seeds in capsules, or bolls; each seed is surrounded with downy fiber, white or creamy in color and easily spun. The fibers flatten and twist naturally as they dry. Cotton is classified in the division Magnoliophyta, class Magnoliopsida, order Malvales, family Malvaceae. Cotton is of tropical origin but is most successfully cultivated in temperate climates with well-distributed rainfall. It is planted annually by seed in furrows; the plants are thinned and weeded during the spring growing season. Diseases and insect pests are numerous; of these the most destructive has been the boll weevil, which has caused enormous losses. Genetically altered strains of cotton are being developed that can resist infestation by some insects and damage by application of herbicides. Mechanical harvesting is preceded by a chemical-defolian...

Tobacco, name for any plant of the genus Nicotiana of the Solanaceae family (nightshade family) and for the product manufactured from the leaf and used in cigars and cigarettes, snuff, and pipe and chewing tobacco. Tobacco plants are also used in plant bioengineering, and some of the 60 species are grown as ornamentals. The chief commercial species, N. tabacum, is believed native to tropical America, like most nicotiana plants, but has been so long cultivated that it is no longer known in the wild. N. rustica, a mild-flavored, fast-burning species, was the tobacco originally raised in Virginia, but it is now grown chiefly in Turkey, India, and Russia. The alkaloid nicotine is the most characteristic constituent of tobacco and is responsible for its addictive nature. The possible harmful effects of the nicotine, tarry compounds, and carbon monoxide in tobacco smoke vary with the individual's tolerance.