Kids Research Express

Barley, common name for any of a genus of cereal grass, native to Asia and Ethiopia, and one of the most ancient of cultivated plants (see Grasses ). Its cultivation is mentioned in the Bible, and it was grown by the ancient Egyptians, Greeks, Romans, and Chinese. It is now the fourth largest grain crop, after wheat, rice, and corn. In the United States and Canada, as well as in the greater portion of Europe, barley is sown in the spring. Along the Mediterranean Sea and in parts of California and Arizona, it is sown in the fall. It is also grown as a winter annual in the southern United States. Drought resistant and hardy, barley can be grown on marginal cropland; salt-resistant strains are being developed to increase its usefulness in coastal regions. Barley germinates at about the same temperature as wheat. The different cultivated varieties of barley belong to three distinct types: two-rowed barley, six-rowed barley, and irregular barley. The varieties grown in the United States ar

.. Coffee, common name for any of a genus of trees of the madder family, and also for their seeds (beans) and for the beverage brewed from them. Of the 30 or more species of the genus, only three are important: Arabian, robusta, and Liberian. The shrub or small tree, 4.6 to 6 m (15 to 20 ft) high at maturity, bears shiny green, ovate leaves that persist for three to five years and white, fragrant flowers that bloom for only a few days. During the six or seven months after appearance of the flower, the fruit develops, changing from light green to red and, ultimately, when fully ripe and ready for picking, to deep crimson. The mature fruit, which resembles a cherry, grows in clusters attached to the limb by very short stems, and it usually contains two seeds, or beans, surrounded by a sweet pulp. CHARACTERISTICS Coffee contains a complex mixture of chemical components of the bean, some of which are not affected by roasting. Other compounds, particularly those related to the aroma, are pr

Vegetable, the edible product of a herbaceous plant—that is, a plant with a soft stem, as distinguished from the edible nuts and fruits produced by plants with woody stems such as shrubs and trees. Vegetables can be grouped according to the edible part of each plant: leaves (lettuce), stalks (celery), roots (carrot), tubers (potato), bulbs (onion), and flowers (broccoli). In addition, fruits such as the tomato and seeds such as the pea are commonly considered vegetables. Most vegetables are valuable sources of vitamins, minerals, and fiber and are low in fat and calories. With cereals and legumes, they are important to a healthy diet (see Human Nutrition ). See also Cereals ; Fruit ; Legume ; Nut .

Bark, hard covering or rind of the stem, branches, and roots of a tree or other plant, as distinguished from the wood. The bark consists of an inner and outer layer. Bark is used commercially in the tanning of leather, in boatbuilding, and in basket making and in the manufacture of clothing and shoes, food flavoring, medicine, and cork and cork products. Barks rich in tannin are usually used for tanning, although other properties also determine the value of a bark for preparing leather. Bark from several species of oak in the genus Quercus and from the Eastern hemlock (Tsuga canadensis) used to supply much of the tannin in the northern United States. In recent years, however, use of the wood or fruit of many other trees and the development of synthetic tannins have replaced earlier sources.

Autumn Crocus, common name for a bulbous herb (see Lily ). Native to Europe and not a true crocus , this garden plant, which is also called meadow saffron , takes its name from its unusual pattern of flowering. In spring, several large, straplike leaves grow from the bulb , more or less erect, to a height of 60 cm (24 in) or more. When the leaves fall off in the autumn, clusters of purple or white crocuslike flowers appear. Autumn crocus contains poisonous alkaloids , the principal one being colchicine. Scientific classification: The autumn crocus belongs to the family Liliaceae. It is classified as Colchicum autumnale.

Bulb, mass of overlapping, usually fleshy leaves on a short stem, enclosing, protecting, and serving as a source of food for at least one bud that may develop into a new plant. The bulb, usually developed underground, has roots growing down from the stem. The truncated bulb, as in the onion, has tightly overlapping leaves; the scaly bulb, as in garlic, is looser. In common usage the term bulb also refers to bulblike stems, such as the corm of the crocus or the tuber of the dahlia, and even to rhizomes, masses of roots, and some underground stems. See also Rhizome; Tuber .

Archaea or Archaebacteria, common name for a group of one-celled organisms, many of which do not require oxygen or sunlight to live. Before the discovery of archaebacteria, scientists divided all living organisms into prokaryotes (organisms without a cellular nucleus), which consisted primarily of bacteria , and eukaryotes (organisms with a cellular nucleus), which consisted of fungi, plants, and animals. Archaebacteria were initially grouped with bacteria because like bacteria, they lack a well-defined nucleus. Recent evidence, however, has demonstrated that archaebacteria have a genetic makeup that more closely resembles the eukaryotes, organisms that have a well-defined nucleus. This unique structure means that archaebacteria cannot be accurately grouped with either the prokaryotes or the eukaryotes. Instead, scientists have proposed that these microorganisms be classified in a new branch of life, or domain, called archaea. Archaebacteria often live in extreme conditions that wer

Chrysanthemum, common name for numerous perennials formerly included in only a single genus of the composite flower family, but now classified in several separate genera of the family. Commercial or florists' varieties of chrysanthemums and the garden mums have large, globular heads in which the ray flowers are greatly multiplied, while the disk flowers are unnoticeable or even absent. Numerous hybrids have been developed with single, semidouble, or double blossoms that grow up to 20 cm (8 in) in diameter. The terms pompon and button are applied to small, globular flowers, the term anemone to flowers with twisted rays, and the term decorative to loose, open flowers with flat, grooved, or tubular rays. When tubular rays are open and flattened at the tips, the plants are called spoon mums. Other varieties are sometimes described as feathery, plumed, or spidery. The flowers are produced in all shades of bronze, brown, purple, red, pink, yellow, and white. Scientific classification: C

Gibberellin, one of the groups of hormones that influence the growth of plants. They are chemical substances that occur naturally in many plants and regulate various important functions, such as the elongation of flowering stems, the creation of proteins, and the germination of some plant seeds. Unlike auxins , which are plant hormones that form in the plant’s top shoots and flow downward to affect the growth of plant parts, gibberellins form in the seeds, young leaves, and plant roots before flowing upward into the stem. Gibberellins were discovered in 1926 by Japanese scientists investigating foolish-seedling disease in rice. This disease caused rice shoots to grow extremely long without corresponding root growth. As a result, the seedlings did not flower and usually died before maturity. Foolish-seedling disease was traced to the fungus Gibberella fujikuroi, which produces substances now known as gibberellins. More than 50 different gibberellins have been isolated and identified; th

Auxin, any of a group of plant hormones, substances naturally produced in actively growing parts of plants that regulate many aspects of plant growth and development. These substances affect the growth of the stem tip, leaves, and roots, and the development of side branches and fruit. Auxins affect the growth of these plant parts by stimulating certain cells to elongate, or lengthen, and by inhibiting the growth of other cells, depending on the amount and distribution of auxin in the plant tissue. The effect of auxin on plant cells is important in controlling plant functions called tropisms. A tropism is a plant’s response to external stimuli that causes a change in the direction of the plant’s growth, such as bending, turning, or curving. When an indoor plant is placed in a sunlit window, the plant appears to bend or grow toward the sun. This response to the stimulus of light is called phototropism. It is believed that light destroys auxin where it strikes the stem, causing an imbalan

Digitalis, genus of plants of the figwort family. One species introduced from Europe, the common foxglove, is a self-seeding biennial or perennial herb, widely grown in gardens and naturalized along roadsides and in meadows or logged-off areas, especially in the western United States. The naturalized plant bears a showy, terminal cluster of hanging, tubular, spotted, purple flowers. Cultivated varieties are of various colors and markings. The erect stems are about 91 cm (about 36 in) tall with numerous large, thick leaves at the base. Digitalis, a drug prepared from digitalin, a glycoside obtained from the common foxglove, is used in medicine. With techniques of modern pharmacology, about a dozen steroid glycosides have been isolated from the leaves. The best known of these exert a twofold action on the heart that results in a more effective heartbeat. These medicines strengthen the force of contraction and, at the same time, slow the beat so that the period of relaxation between be

Classification of Insectivorous Plants Plants that obtain at least some of their nutrition by capturing and digesting prey are called insectivorous, or carnivorous, plants. Such plants have adaptations that allow them to attract, catch, and break down or digest prey once it is caught. Estimates of the number of species of carnivorous plants number from 450 to more than 600. Generally, these plants are classified into genera based upon the mechanism they have for trapping and capturing their prey. The major genera of these plants are listed below. Common name Scientific name Trapping mechanism bladderwort Utricularia vulgaris active trap; shows rapid motion during capture butterwort Pinguicula vulgaris semiactive trap; two-stage trap in which prey is initially caught in sticky fluid California pitcher plant Darlingtonia californica passive trap; attracts prey with nectar and then drowns prey in fluid contained within plant flypaper plant Byblis liniflora passiv

Insectivorous Plants, also carnivorous plants, plants that gain some of their nutrition from animals, especially insects, captured by the plants themselves. Most occur in bogs where the soil is acid and poor in available nitrogen; capturing insects is one way of getting nitrogenous compounds without manufacturing them. At the same time, the green leaves of these plants manufacture carbohydrates. The trapping mechanism of insectivorous plants is relatively small. Therefore, prey is almost inevitably limited to small insects. Insectivorous plants are diverse and represent members of three orders of dicots : Nepenthales, Scrophulariales, and Rosales. A majority are in the Nepenthales, including the pitcher plant , sundews and the Venus's-flytrap, and East Indian pitcher plants. Others include the bladderworts, butterworts, and the Australian pitcher plant. Discussed below are the sundews and bladderworts. Certain species of fungus are known to be carnivorous as well. Venus’s-Flytrap

Saffron, bright-yellow flavoring and coloring material, consisting of the dried stigmas and style branches of the saffron crocus, the bulbs of which were introduced to Europe from Asia Minor.

Biennial, any plant that normally requires two years for its life cycle. Biennials store food in the first season of their growth, flower and bear fruit in the second season, and then die. Familiar examples are foxglove, hollyhock, and pansy. Many cultivated vegetables are biennials, for example, carrots, turnips, parsnips, parsley, and celery. Biennials often become annuals when early sowing or warm weather causes the earlier development of a flowering stem. Less hardy varieties are often routinely treated as annuals.

Herb, in botany , soft-tissued plant that does not develop permanent woody tissues above ground. Such plants may be annual, biennial , or perennial. Herbaceous plants are generally considered to include soft-tissued angiosperms, or flowering plants, but may also include the ferns, club mosses , and horsetails. The term herb is applied by pharmacists to any plant or plant part that has medicinal properties. Herb parts that are used as food or seasoning are called culinary herbs or potherbs. Relaed Topics: Spices Types of Spices and Herbs Culinary Herbs Fragrant Herbs Medicinal Herbs Parasitic Herbs

Crocus, genus of hardy perennial plants, of the iris family, native to southern Europe and Asia and widely cultivated. Crocuses produce a single tubular flower and grasslike leaves growing from a corm, or underground stem base. Common autumnal species include the saffron crocus, which has a bright lilac flower from which the dye and flavoring agent saffron is made, and a crocus whose flowers are a more delicate shade of lilac. The yellow cloth-of-gold crocus is one of the earliest blooming flowers in temperate climates. Other spring species are the Dutch crocus, which is also yellow, and the early crocus with lilac or white flowers. See also Autumn Crocus . Scientific classification: Crocuses belong to the family Iridaceae. The saffron crocus is classified as Crocus sativus and the autumnal species with flowers of a more delicate shade of lilac as Crocus speciosus. The yellow cloth-of-gold crocus is classified as Crocus susianus, the Dutch crocus as Crocus moesiacus, and the early croc

Tulip, common name for any member of a genus of spring-flowering, bulbous herbs, of the lily family. About 80 species of tulip exist; these plants are native to Asia and the Mediterranean region, and thousands of varieties are widely cultivated as garden flowers. Tulips are erect plants with long, broad, parallel-veined leaves and cup-shaped, solitary flowers borne at the tip of the stem. The flowers are either single or double and occur in a wide range of solid colors. Some, called broken tulips, are varicolored as a result of a viral disease carried and transferred to the plants by aphids. The garden tulip was introduced into western Europe from Constantinople (present-day İstanbul) in the 16th century and soon achieved great popularity. Interest in tulip growing mounted, especially in Holland, where it developed by 1634 into a craze called tulipomania. Wild speculation in tulip stock ensued, and enormous prices were paid for single bulbs. After many people had gone bankrupt, the cr

With only a few exceptions, the true cacti are found exclusively in the western hemisphere, from Canada to the southern tip of South America, the West Indies, and the Galápagos Islands. Cacti are often referred to as xerophytes, plants adapted to extremely dry conditions and capable of withstanding drying for extended periods. The most obvious characteristic of cacti are the spines, which serve a number of purposes besides protection, such as casting shadows on the cactus to protect it from the sun, reducing leaf surface area, which reduces water loss, and serving as points of condensation for moisture, which then drips down for use by the roots. Christmas Cactus The Christmas cacti are a group of bushy perennial cacti growing to a height of about 16 cm (5 in). These cacti are often found in shaded areas in rich, well-drained soils. Organ Pipe Cactus The organ pipe cactus grows in parts of Arizona, Baja California, and northern Mexico at elevations below 1000 m (3000 ft). The organ pip

Cactus, common name for the family comprising a peculiar group of spiny, fleshy plants native to America. The family contains about 1650 species, most of which are adapted to arid climates. The fruits of cacti are important sources of food and drink in many areas to which they are native. Because cacti require little care and exhibit bizarre forms, they are popular for home cultivation and are coming under increasing pressure as a result. More than 17 kinds of cacti now face extinction because of plundering by avid collectors and professional poachers, especially in the southwestern United States and northern Mexico. Cactus plants usually consist of spiny stems and roots. Leaves are greatly reduced or entirely absent. Only in two genera are fully formed leaves present. The stems of cacti are usually swollen and fleshy, adapted to water storage, and many are shaped in ways that cause rain to flow directly to the root system for absorption. The roots form extensive systems near the soil

Grape, common name of an edible fruit in the buckthorn family, and of the vines that produce the fruit. The European grape has been used as food since prehistoric times. Grape seeds have been found in remains of lake dwellings of the Bronze Age in Switzerland and Italy and in tombs of ancient Egypt. Botanists believe that the Caspian Sea region was the original home of the European grape. Distribution of seeds by birds, wind, and water carried the plant westward to the Asian shores of the Mediterranean. Grape culture, practiced in Palestine during biblical times, was introduced in the Mediterranean region by seagoing Phoenicians. The ancient Greeks cultivated grapes, and use of the fruit was later adopted by Rome and its tributary territories. Grapevines are stems that climb on walls and fences by means of specialized supporting organs, called tendrils. Palmately veined leaves arise alternately along the stem. In most varieties, tendrils arise opposite two of every three successive lea

Hawthorn, common name for any of a genus of small trees of the rose family. Hawthorns are native to temperate regions and are widely cultivated in the form of hedges. They have dense, sharply thorned branches; single, irregularly toothed leaves that turn to brilliant colors in autumn; tiny, red fruits even throughout the winter; and fragrant, white flowers borne in clusters. The best-known species is the English hawthorn, also called the mayflower. Species native to the United States include the Washington hawthorn, found in the southern states, and the cockspur hawthorn, an eastern species with shiny leaves and long thorns. The genus includes about 20 species in Eurasia and more than 100 in North America. Many of the latter are believed to be hybrids. Scientific classification: Hawthorns belong to the family Rosaceae. The English hawthorn is classified as Crataegus laevigata, the Washington hawthorn as Crataegus phaenopyrum, and the cockspur hawthorn as Crataegus crus-galli.

Rose, common name for a medium-size family of flowering plants with many important fruit and ornamental species, and for its representative genus. Worldwide in distribution, the rose family contains about 107 genera and 3100 species. The rose family is placed in an order with 24 other families. This order is sometimes referred to as the rose order. Other important members of the order include the saxifrage family and the stonecrop family. Another family, the coco-plum family, occurs in the lowland Tropics and contains about 400 species, several of which are used locally for their timber, oilseeds, and fruits. Perhaps the best-known member of the family is the coco plum, found in southern Florida on sandy beaches and swamps; its sweet fruits are made into jelly or preserves. About 70 genera of the rose family are cultivated for food, ornament, flowers, timber, or other uses. Although worldwide in distribution, the family is most abundant in north temperate regions and contains many

Cereals, various species of the grass family, cultivated for their seed, which is used as food. The name is derived from Ceres, the Roman goddess of grains and agriculture. Although the cereals proper do not belong to any particular tribe of the grasses, the use of particular species as bread plants seems to have been determined chiefly by the superior size of the seed or by the ease of procuring it in sufficient quantity and of freeing it from its inedible covering. The most extensively cultivated grains are wheat , barley , rye , oats , rice , corn or maize, different kinds of millet, and the grain sorghums known as durra or guinea corn. These have all been cultivated since ancient times. Maize and wild rice are the only grains that originated in the Americas; the others were developed in Europe, Asia, and Africa. Scientific classification: Cereals belong to the family Poaceae (formerly Gramineae). Wheat is classified in the genus Triticum, barley in the genus Hordeum, rye in the