common cold, acute viral infection that starts in the upper respiratory tract, sometimes spreads to the lower respiratory structures, and may cause secondary infections in the eyes or middle ears. More than 200 agents can cause symptoms of the common cold, including parainfluenza, influenza,

coleus: Varieties of common coleus, or painted nettle (Plectranthus scutellarioides, formerly Coleus blumei), from Java, are well-known house and garden plants up to one metre (three feet) tall. They have square stems and small, blue, two-lipped flowers borne in spikes. The leaves are often variegated with colourful patterns…

collared lizard: The common collared lizard, C. collaris, reaches 35 cm (14 inches) long, and the tail alone accounts for two-thirds of the animal’s total length. Males are larger than females. In the eastern part of its range, the collared lizard is often referred to as “the mountain…

comfrey: …family Boraginaceae, especially the medicinal common comfrey (S. officinale), used to treat wounds and a source of a gum for treatment of wool. The coiled sprays of comfrey blooms, which are bell-like, deeply parted, five-lobed, and hanging, are usually pollinated by bees.

cormorant: …the common, or great, cormorant, Phalacrocorax carbo; white-cheeked, and up to 100 cm (40 inches) long, it breeds from eastern Canada to Iceland, across Eurasia to Australia and New Zealand, and in parts of Africa. It and the slightly smaller Japanese cormorant, P. capillatus, are the species

cottonwood: Eastern cottonwood (P. deltoides), nearly 30 metres (100 feet) tall, has thick glossy leaves. A hybrid between this and Eurasian black poplar (P. nigra) is P. canadensis. Alamo, or Fremont cottonwood (P. fremontii), tallest of the group, is found in southwestern North America. Great Plains…

coucal: sinensis), called crow pheasant in India, is 48 to 56 cm (19 to 22 inches) long. It is black with brown mantle and wings. Its range is from India to southern China and Malaysia.

cow parsnip: Common cow parsnip (H. lanatum or H. maximum) is a weedy plant native to North America. It grows to more than 2 metres (7 feet) in height and produces white flower clusters that are nearly 20 cm (8 inches) in diameter.

crab: Economic importance: …important and valuable are the edible crab of the British and European coasts (Cancer pagurus) and, in North America, the blue crab (Callinectes sapidus) of the Atlantic coast and the Dungeness crab (Cancer magister) of the Pacific coast. In the Indo-Pacific region the swimming crabs, Scylla and Portunus, related to…

cuckoo: …modifiers, refers to the most common local form, elsewhere called the common, or European, cuckoo (Cuculus canorus). Many cuckoos have specialized names, such as ani, coua, coucal, guira, and roadrunner. Members of the subfamily Neomorphinae are called ground cuckoos.

curlew: The common, or Eurasian, curlew (N. arquata), almost 60 cm (24 inches) long including the bill, is the largest European shorebird. This species breeds from Britain to Central Asia.

curly mesquite: …species are important range grasses; common curly mesquite (Hilaria belangeri) and James’s galleta (H. jamesii) are particularly palatable to livestock when fresh and green.

ribes: Major species: …and common, or garden or red, currant (R. rubrum).

Annonaceae: Major genera and species: The custard apple (A. reticulata), a small tropical American tree, gives the family one of its common names. Also known as bullock’s-heart for its globose shape, it has fruits with creamy white, sweetish, custardlike flesh. Cherimoya (A. cherimola), soursop (A. muricata), and sweetsop (A. squamosa) are…

cypress pine: Major species: …of southeastern Australia; and the common cypress pine (C. preissii) of southern Australia, often shrubby near the seacoast, with one subspecies called slender pine and another known as turpentine pine. Most of these timber trees are about 25 metres (about 80 feet) tall, but the Port Macquarie pine, also planted…

cystitis: Acute cystitis: Acute, or common, cystitis is caused by bacterial infection, frequently as part of a general urinary tract infection (UTI). The mucous membrane of the bladder becomes swollen and red and bleeds. Small ulcers can develop, the surface layer can shred, and small clear cysts (sacs…

daffodil, (Narcissus pseudonarcissus), bulb-forming plant in the amaryllis family, widely cultivated for its showy, trumpetlike flowers, which emerge in the spring. Daffodils are native to northern Europe and are grown in temperate climates around the world. The daffodil’s popularity has resulted

lead processing: The metal and its alloys: Common lead is fully refined and desilvered lead, with low copper content; it is widely used wherever high corrosion resistance is not necessary. Acid lead, made by adding copper to fully refined lead, differs from chemical lead primarily in its higher bismuth content.

dittany: (gas plant; Dictamnus albus), American dittany (common dittany; Cunila origanoides), and dittany of Crete (Cretan dittany, or hop marjoram; Origanum dictamnus). European dittany is in the rue family (Rutaceae), while the other two species are in the mint family (Lamiaceae). All three species are bushy perennials cultivated for their…

diving petrel: …and most widespread is the common diving petrel (Pelecanoides urinatrix), about 16 cm (6.5 inches) long; the largest is the Peruvian diving petrel (P. garnotii), about 25 cm long, restricted to the west coast of South America from about 6° to 37° S.

Erythronium: The common dog’s tooth violet, or adder’s tongue, of North America is E. americanum. It has yellow flowers and brown-mottled leaves. Several species of Erythronium are grown as rock-garden ornamentals.

mahimahi, (Coryphaena hippurus), species of open-ocean fishes known for its iridescent coloring and popularity in commercial and sport fishing. The mahimahi is one of two species classified in the genus Coryphaena, a single genus within the family Coryphaenidae, the other being the pompano

dolphin: …widely recognized species are the common and bottlenose dolphins (Delphinus delphis and Tursiops truncatus, respectively). The bottlenose, characterized by a “built-in smile” formed by the curvature of its mouth, has become a familiar performer in oceanariums. It has also become the subject of scientific studies because of its intelligence and…

mahimahi, (Coryphaena hippurus), species of open-ocean fishes known for its iridescent coloring and popularity in commercial and sport fishing. The mahimahi is one of two species classified in the genus Coryphaena, a single genus within the family Coryphaenidae, the other being the pompano

donkey orchid: The common donkey orchid (Diuris longifolia) bears three to five purplish flowers about 4 cm (1.5 inches) long. Other well-known species are cat’s face (D. filifolia) and nanny-goat orchid (D. laevis).

dwarf mistletoe: The common dwarf mistletoe, A. minutissimum, is one of the smallest plants having specialized water-conducting tissues. Its flowering stems extend less than 3 mm (about 18 inch) from its host plant. The fruits of most Arceuthobium species are about 4 mm long, and each contains a…

eelgrass: Historically, common eelgrass (Zostera marina) was an important tidewater plant whose dried leaves were used for packing glass articles and for stuffing cushions.

egret: The great white egret, Egretta (sometimes Casmerodius) alba, of both hemispheres, is about 90 cm (35 inches) long and bears plumes only on the back. The American populations of this bird are sometimes called American, or common, egrets.

eider: In the common eider (Somateria mollissima), with four or five races, differing mainly in length and colour of bill, the drake is mostly white above with black crown, belly, and tail. Like all eiders, this species is at home in the far north. It breeds along icy…

eland: The common, or Cape, eland (T. oryx) ranges over the woodlands, plains, mountains, and subdeserts of eastern and southern Africa. The eland is the largest of all antelopes.

Dipsacales: Adoxaceae: European, or black, elderberry (Sambucus nigra) is commonly used in herbal medicine.

emu, (Dromaius novaehollandiae), flightless bird of Australia that is the second largest living bird: the emu is more than 1.5 metres (5 feet) tall and may weigh more than 45 kg (100 pounds). The emu is the sole living member of the family Dromaiidae (or Dromiceiidae) of the order Casuariiformes,

history of Europe: Chronology: …the modern notion of the Common Era. The new method superseded older traditions, which included dating by four-year Olympiads, by the number of years since the founding of Rome in 753 bce, by the years of Roman consuls, by the regnal years of emperors, and by the 15-year tax assessment…

brittle star: …Massachusetts to Brazil, and the common European brittle star (Ophiothrix fragilis). Brittle stars typically hide under rocks or in crevices during the day and emerge at night to feed.

plum: The European plum (P. domestica) and the Japanese plum (P. salicina) are grown commercially for their fruits, and a number of species, including the purple-leaf plum (P. cerasifera), are used as ornamental plants for their attractive flowers and leaves.

shrimp: The common European shrimp, or sand shrimp, Crangon vulgaris (Crago septemspinosus), occurs in coastal waters on both sides of the North Atlantic and grows to about 8 cm (3 inches); it is gray or dark brown with brown or reddish spots. The shrimp Peneus setiferus feeds on small plants and…

mental disorder: The psychotherapies: …view is called the “common factors” perspective on psychotherapy.

cisticola: …most widespread example is the zitting cisticola, or common fantail warbler (C. juncidis), a reddish brown, streaky bird, 11 cm (4.5 inches) long, found from Europe and Africa to Japan and Australia. Like most cisticolas it makes a domed nest. The most common species from India to the Philippines and…

perception: Gestalt principles: One Gestalt principle, that of common fate, depends on movement and is quite striking when observed. According to the principle of common fate, stimulus elements are likely to be perceived as a unit if they move together. An illustration of this principle is provided by a well-camouflaged object, such as…

ferret: Common ferret: The common ferret is a domesticated form of the European polecat, which it resembles in size and habits and with which it interbreeds, leading most taxonomists to classify the common ferret as a subspecies. The common ferret is found throughout the European polecat’s…

badger: …pahmi, consist of four species: Chinese (M. moschata), Burmese (M. personata), Everett’s (M. everetti), and Javan (M. orientalis). They live in grasslands and forests from northeast India to central China and Southeast Asia where they consume mostly insects, worms, small birds, rodents, and wild fruits. They are brownish to blackish…

fig: Types and cultivation: …Smyrna, White San Pedro, and Common. Smyrna-type figs develop only when fertile seeds are present, and these seeds account for the generally excellent quality and nutty flavour of the fruit. Figs of the White San Pedro type combine the characteristics of both the Smyrna and the Common type on one…

fire-bellied toad: The common fire-bellied toad (B. bombina) is a pond dweller about 5 centimetres (2 inches) long. When disturbed it raises its forearms and arches its head and hind legs over its back. Resting on the lower part of its tautly curved abdomen, it freezes with the…

North Sea: Fisheries: A unique fisheries arrangement, the Common Fisheries Policy, was adopted by members of the European Community in 1983. Catch quotas are established each year for the various North Sea species beyond territorial sea limits. Allocations of the total catch are then assigned to each member state, thus creating a single…

flax, (Linum usitatissimum), plant of the family Linaceae, cultivated both for its fibre, from which linen yarn and fabric are made, and for its nutritious seeds, called flaxseed or linseed, from which linseed oil is obtained. Though flax has lost some of its value as a commercial fibre crop owing

flowering quince: Major species: The common flowering quince (C. speciosa), frequently used in informal hedges, bears red, pink, or white flowers and grows to about 2 metres (6.6 feet).

European Union: Creation of the European Economic Community: …Political Cooperation (EPC; renamed the Common Foreign and Security Policy by the Maastricht Treaty), consisting of regular meetings of the foreign ministers of each country, was established to coordinate foreign policy. In 1975 the European Regional Development Fund was created to address regional economic disparities and to provide additional resources…

forsythia: Major species: Common forsythia (F. ×intermedia), a hybrid between green-stem forsythia and weeping forsythia, has arching stems and grows up to 3 metres (10 feet) tall with bright yellow flowers. There also are variegated, dwarf, and many-flowered varieties.

red fox, (Vulpes vulpes), species of fox (family Canidae) found throughout Europe, temperate Asia, northern Africa, and North America. It has the largest natural distribution of any land mammal except human beings. First introduced to Australia in the 19th century, it has since established itself

foxglove: Major species and uses: …common, or purple, foxglove (Digitalis purpurea) is a popular garden ornamental, and numerous hybrids and cultivars have been developed in a range of colours. Other garden species include rusty foxglove (D. ferruginea); yellow foxglove (D. grandiflora); straw, or small yellow, foxglove (D. lutea); and chocolate, or small-flowered, foxglove (D.…

arithmetic: Rational numbers: …n/d and is called a common fraction. It may be considered as the quotient of n divided by d. The number d is called the denominator (it determines the fractional unit or denomination), and n is called the numerator (it enumerates the number of fractional units that are taken). The…

Emydidae, family of hard-shelled turtles native to both the Old and New Worlds, primarily in the Northern Hemisphere. The emydid turtles comprise more than 25 genera and 85 living species—roughly one-half of all the genera and one-third of all the species of turtles now living. With the exception

common frog, (species Rana temporaria), largely terrestrial frog (family Ranidae), native to Europe, from Great Britain to central Russia. It is known in continental Europe as either grass frog or russet frog. The common frog is smooth-skinned, and adults are 7 to 10 cm (2.8 to 3.9 inches) long.

Hydrocharitaceae: The common frog’s-bit (Hydrocharis morsus-ranae), from which the family receives its common name, is an ornamental rootless water plant with round or heart-shaped floating leaves and small attractive three-petaled white flowers. The water soldier (Stratiotes aloides) bears rosettes of tough sharp-edged leaves that float in summer…

fumitory: Common, or drug, fumitory (Fumaria officinalis) is a 90-cm- (3-foot-) tall climbing plant with lacy leaves and spikelike sprays of white or pinkish tubular flowers. The plant is native to Europe and Asia and has naturalized in parts of North America, having escaped cultivation. Once regarded as a medicinal…

United Nations Conference on Trade and Development: …among participating developing countries; the Common Fund for Commodities (1989), an intergovernmental financial institution that provides assistance to developing countries that are heavily dependent on commodity exports; and various agreements for debt relief. In the 1990s UNCTAD’s efforts were directed toward the challenges globalization poses to developing countries, and special…

moorhen, bird species also called common gallinule. See

list of birth month flowers: October: Cosmos (usually Cosmos bipinnatus) are popular garden flowers with airy blooms in pinks and whites. Other varieties are a bit more moody and come in fall colors such as burgundy and orange. Musky marigolds (namely Tagetes erecta) are perfect for harvest time and have long been associated…

Many people are familiar with the friendly ladybug or handled a woolly bear caterpillar as a child, but fewer, perhaps, are aware of a ladybug’s larval stage or know what a woolly bear caterpillar turns into as an adult. The following is a list of both the adult and larval forms of a few common

iris: Major species: …or German, group—the common garden irises. These are largely hybrids of pale blue Iris pallida, yellow I. variegata, purple-blue I. germanica, and perhaps other southern European species. They are hardy rhizomatous types with sturdy swordlike leaves and tall stems (to 90 cm [3 feet]) of three to many flowers. With…

petunia: The common garden petunia (Petunia ×atkinsiana) is an ornamental plant whose showy trumpet-shaped flowers make it popular for summer flower beds and window boxes.

verbena: The common garden verbena (Glandularia × hybrida, formerly Verbena hybrida) is a square-stemmed creeping plant that bears flat heads of phloxlike flowers in a range of colours. Clump verbena, or rose verbena (Glandularia canadensis, formerly V. canadensis), is also sometimes cultivated for garden flowers.

garter snake: …more defensive species is the common garter snake (Thamnophis sirtalis), probably North America’s most widely distributed reptile. The ribbon snake (T. sauritus), small and slender, is a strongly striped form. Garter snakes live chiefly on insects, earthworms, and amphibians; the western ribbon snake (T.

common gateway interface (CGI), a standard that allows external applications located on personal computers or other devices to interact with information servers on the Internet. Developed in the 1990s, CGI is still used, but other methods such as PHP scripts are also utilized. CGI programs are

runic alphabet: …main varieties of runic script: Early, or Common, Germanic (Teutonic), used in northern Europe before about 800 ad; Anglo-Saxon, or Anglian, used in Britain from the 5th or 6th century to about the 12th century ad; and Nordic, or Scandinavian, used from the 8th to about the 12th or 13th…

ginger, (Zingiber officinale), herbaceous perennial plant of the family Zingiberaceae, probably native to southeastern Asia, or its pungent aromatic rhizome (underground stem) used as a spice, flavouring, food, and medicine. Ginger’s generic name, Zingiber, is derived from the Greek zingiberis,

glory-bower: Common glory-bower (C. speciosissimum), from Asia, is a shrub up to about 120 cm (4 feet) tall that produces clusters of flame-orange flowers above heart-shaped bronzy leaves about 30 cm (1 foot) long.

firefly: The common glowworm (Lampyris noctiluca) is a member of this family (see glowworm).

common good, that which benefits society as a whole, in contrast to the private good of individuals and sections of society. From the era of the ancient Greek city-states through contemporary political philosophy, the idea of the common good has pointed toward the possibility that certain goods,

gorse: Common gorse (U. europaeus) is a spiny, yellow-flowered leguminous shrub native to Europe and naturalized in the Middle Atlantic states and on Vancouver Island. The large green spines and green twigs of Spanish gorse (G. hispanica), native to Spain and northern Italy, make it appear…

grackle: The common grackle (Quiscalus quiscula) of North America is about 30 cm (12 inches) long. In the great-tailed and boat-tailed grackles (Cassidix mexicanus and C. major), the male has a long, deeply keeled tail: his total length may be 43 cm. These species are found in…

water snake: The common grass snake (N. natrix), which is the most terrestrial of the water snakes, inhabits all of Europe and western Asia. It is olive-coloured, green, or gray, with a yellow or white collar on the neck. Adults range in length from 0.6 to 1 metre…

rat opossum: 4 ounces) in the common gray shrew opossum (Caenolestes fuliginosus). The muzzle is long and narrow. The fur of the head and body is dark slate gray, with the underparts of the body being slightly paler in most species. The ears and tail are covered with short fine hair.…

rat opossum: 4 ounces) in the common gray shrew opossum (Caenolestes fuliginosus). The muzzle is long and narrow. The fur of the head and body is dark slate gray, with the underparts of the body being slightly paler in most species. The ears and tail are covered with short fine hair.…

vulture: Old World vultures: The common griffon vulture (Gyps fulvus), or Eurasian griffon, is an Old World vulture of northwestern Africa, the Spanish highlands, southern Russia, and the Balkans. Gray above and reddish brown with white streaking below, it is about one metre (three feet) long. The genus Gyps contains…

Louis Adamic: Starting in 1940, he edited Common Ground, a magazine that analyzed the interracial culture of the United States.

guava, (Psidium guajava), small tropical tree or shrub of the family Myrtaceae, cultivated for its edible fruits. Guava trees are native to tropical America and are grown in tropical and subtropical areas worldwide. Guava fruits are processed into jams, jellies, and preserves and are common pastry

murre: The common murre (U. aalge) breeds from the Arctic Circle south to Nova Scotia, California, Portugal, and Korea. Atlantic populations include the so-called bridled, or ringed, murre, a mutation that shows, in breeding season, a ring around the eye and a thin, white stripe behind the…

gundi: Common gundis (Ctenodactylus gundi and C. vali) are found in parts of Morocco, Algeria, Tunisia, and Libya, but the Mzab gundi (Massoutiera mzabi) has the largest range, extending from southeastern Algeria through southwestern Libya to northern Mali, Niger, and Chad. The Felou gundi (Felovia vae)…

moonrat, (Echinosorex gymnura), a large Southeast Asian insectivore that is essentially a primitive tropical hedgehog with a long tail and fur instead of spines. Despite their name, moonrats are not rodents, although they have a slim body, small unpigmented ears, small eyes, and a tapered muzzle

hamster: The largest is the common hamster (Cricetus cricetus), measuring up to 34 cm long, not including a short tail of up to 6 cm.

barbet: …repetitious species are sometimes called brain-fever birds.

hawthorn: Common species: …are the common hawthorn (Crataegus monogyna) and the smooth hawthorn, also known as whitethorn, (C. laevigata). The smooth hawthorn has given rise to several cultivated varieties with showier flower clusters in pink and red, though it and other ornamental species often suffer from leaf spot, fire blight, and cedar…

hedgehog: 5 pounds), but the common western European hedgehog (Erinaceus europaeus) can grow to 1,100 grams. Body length is 14 to 30 cm (5.5 to 12 inches), and there is a stumpy and sparsely furred tail measuring 1 to 6 cm. In addition to the three species of Eurasian hedgehogs (genus…

human digestive system: Gross anatomy: …the exit point for the hepatic ducts. These channels are the final pathway for a network of smaller bile ductules interspersed throughout the liver that serve to carry newly formed bile from liver cells to the small intestine via the biliary tract.

common but differentiated responsibilities: …to the notion of “common heritage of mankind,” acknowledged by a 1967 UN resolution that had first emerged as an expression of concern for the loss of natural resources belonging to all (especially maritime, such as whales and tuna). The 1992 UN negotiations were organized around the four key…

heron: …the similar but slightly smaller gray, or common, heron (A. cinerea), widespread in the Old World. Largest of all is the goliath heron (A. goliath) of Africa, a 150-cm (59-inch) bird with a reddish head and neck. The purple heron (A. purpurea) is a darker and smaller Old World form.

migration: Oceanodromous fish: Herring (Clupea harengus), extensively studied because of their economic importance, are the best known of the oceanodromous type and can be classified into several populations, or local races, which do not mix freely. In addition, each has a particular migratory behaviour. In the North Sea, distinct…

hippopotamus, (Hippopotamus amphibius), amphibious African ungulate mammal. Often considered to be the second largest land animal (after the elephant), the hippopotamus is comparable in size and weight to the white rhinoceros (Ceratotherium simum) and the Indian rhinoceros (Rhinoceros unicornis).

cow parsnip: Common hogweed, or eltrot (H. sphondylium), is native to Eurasia and has naturalized in eastern North America. Giant hogweed (H. mantegazzianum) is native to the Caucasus but is considered an invasive species in many areas outside its native range. That striking plant can attain a…

locust: The honey locust (Gleditsia triacanthos), also of the pea family, is a North American tree commonly used as an ornamental and often found in hedges.

beer: Hops: Several varieties of hops (Humulus lupulus) are selected and bred for the bitter and aromatic qualities that they lend to brewing. The female flowers, or cones, produce tiny glands that contain the chemicals of value in brewing. Humulones are the chemical constituents extracted during wort boiling. One fraction of…

horse chestnut: The tree’s common name is said to come from Turkey, where the nuts were fed to horses to cure broken wind.

horsetail: …America and Eurasia is the common horsetail (E. arvense), about 30 cm (1 foot) tall. The central cavity of each stem is about a quarter of its outside diameter. Fairly thick, solid branches arise from below the sheaths, circling the shoots like spokes on a wheel. Stems that bear terminal…

echeveria: Many are popularly called hen-and-chicks because of the way new plantlets, or offsets, develop in a cluster around the parent plant. The usually broad fleshy leaves have waxy, velvety, or powdery surfaces and are often iridescent and sometimes red-edged when in bright sunlight. Echeverias are popular with collectors of…

huckleberry: Major species: The common huckleberry (Gaylussacia baccata) of the eastern United States and Canada is also called black, or high-bush, huckleberry. Dwarf huckleberry (G. dumosa) extends from Florida to Newfoundland. Box huckleberry (G. brachycera), native to the eastern and central United States, can form huge clones, some of…

Cornales: Hydrangeaceae: The common hydrangea, or hortensia (H. macrophylla), is popular with horticulturists and is sold as a potted plant in cool areas. Hydrangea flowers are produced in large, showy white, blue, or pink clusters, with the flower colour of some species being related to soil acidity. The…

reptile: Embryonic development and parental care: For example, the common, or green, iguana (I. iguana) digs a deep burrow with a combination of its fore- and hind limbs; this chamber is often so deep that the female is totally hidden from view. At the end of this burrow, she lays her eggs and fills…

jasmine: Major species: Common jasmine, or poet’s jasmine (Jasminum officinale), native to Iran, produces fragrant white flowers that are the source of attar of jasmine used in perfumery. It is widely cultivated for its shining leaves and clusters of flowers that bloom in summer. Winter jasmine (J. nudiflorum),…

jujube: Most are varieties of the common jujube (Z. jujuba), native to China, where they have been cultivated for more than 4,000 years. This species, 7.6 to 9 metres (25 to 30 feet) high, has alternate, three-veined, elliptical to ovate leaves 2.5 to 7.6 cm (1 to 3 inches) long. The…