reindeer moss: see lichen.

peat moss: see sphagnum.

moss animal, common name applied to members of the phylum Ectoprocta.

moss agate: see agate.

moss, any species of the class Bryopsida, in which the liverworts are sometimes included. Mosses and liverworts together comprise the division Bryophyta, the first green land plants to develop in the process of evolution. It is believed that they evolved from certain very primitive vascular plants and have not given rise to any other type of plant. Their rootlike rhizomes and leaflike processes lack the vascular structure (xylem and phloem) of the true roots, stems, and leaves found in higher plants. Although limited to moist habitats because they require water for fertilization, bryophytes are usually extremely hardy and grow everywhere except in the sea. Mosses, the more complex class structurally, usually grow vertically rather than horizontally, like the liverworts. The green moss plant visible to the naked eye, seldom over 6 in. (15.2 cm) in height, is the gametophyte generation (see reproduction). Except for the commercially valuable sphagnum or peat moss, mosses are of little direct importance to humans. They are of some value in soil formation and filling in of barren habitats (e.g., dried lakes) prior to the growth of higher plants and also provide food for certain animals. Unrelated plants sharing the name moss include the club moss, flowering moss, or pyxie (of the diapensia family), Irish moss, or carrageen (see algae), reindeer moss (a lichen), and Spanish moss. Mosses are classified in the division Bryophyta, class Bryopsida.

club moss, name generally used for the living species of the class Lycopodiopsida, a primitive subdivision of vascular plants. The Lycopodiopsida were a dominant plant group in the Carboniferous period, when they attained the size of trees, and contributed to the coal deposits then being formed. They are now considered relictual. Although they resemble the mosses, they are considered to be evolutionarily more advanced because they are vascular, that is they have specialized fluid-conducting tissues. Club mosses are usually creeping or epiphytic and often inhabit moist places, especially in tropical and subtropical forests. They reproduce by means of spores, either clustered into small cones or borne in the axils of the small scalelike leaves. The principal genera are Lycopodium and Selaginella. Some species of Lycopodium are called ground pine or creeping cedar, especially those that resemble miniature hemlocks with flattened fan-shaped branches, and are often used for Christmas decorations. The spores of L. clavatum are gathered and sold as lycopodium powder, or vegetable sulfur, a highly inflammable yellow powder sometimes used for pharmaceutical purposes (e.g., as an absorptive powder) and in fireworks. Selaginella species, often incorrectly called Lycopodium, are occasionally grown as ornamentals. One of the best known is a resurrection plant. Club mosses constitute the division Lycopodiophyta, class Lycopodiopsida.

Spanish moss, fibrous grayish-green epiphyte (Tillandsia usneoides) that hangs on trees of tropical America and the Southern states, also called Florida, southern, or long moss. It is not a true moss but a member of the pineapple family, and has inconspicuous flowers. It is used for stuffing furniture and as a packing material. Spanish moss is classified in the division Magnoliophyta, class Liliopsida, order Bromeliales, family Bromeliaceae.

Moss, city (1995 pop. 25,253), capital of Østfold co., SE Norway, a port on the Oslofjord. It is a commercial, industrial, and tourist center, with shipyards, sawmills, textile factories, metalworks, and breweries. On Aug. 14, 1814, the convention establishing the personal union of Sweden and Norway was signed there.

Jaffna moss: see agar.

Irish moss: see seaweed; Rhodophyta.

Iceland moss: see lichen.

Hart, Moss, 1904-61, American dramatist, b. New York City, studied at Columbia. His first important play, Once in a Lifetime (1930), marked the beginning of a long collaboration with George S. Kaufman. Among their other successful comedies are Merrily We Roll Along (1934), You Can't Take It with You (1936; Pulitzer Prize), I'd Rather Be Right (1937, written with George M. Cohan), The Man Who Came to Dinner (1939), and George Washington Slept Here (1940). Hart also collaborated on musicals with Irving Berlin and Cole Porter, and his most successful musical, Lady in the Dark (1941), was written with Kurt Weill and Ira Gershwin. Among his plays, produced between 1941 and 1952, are Winged Victory, Christopher Blake, Light Up the Sky, and The Climate of Eden. Hart also directed several 1940s film comedies and wrote the 1952 screen hit Hans Christian Andersen. In 1956 he returned to Broadway as director of the long-running musical hit My Fair Lady.

or sphagnum moss

Any of more than 160 species of plants that make up the bryophyte genus Sphagnum, which grow in dense clumps around ponds, in swamps and bogs, on moist, acid cliffs, and on lakeshores from tropical to subpolar regions. These pale-green to deep-red plants can hold 20 times their weight in water. As they die and are compressed, they form organic peat, which is harvested and dried as fuel, as seedbed cover, and as shipping packaging for plants and live aquatic animals. Gardeners stir peat into soil to increase soil moisture, porosity, and acidity and to reduce erosion.

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Aquatic invertebrate of the phylum Bryozoa (“moss animals”), members (called zooids) of which form colonies. Each zooid is a complete and fully organized animal. Species range in size from a one-zooid “colony” small enough (less than 0.04 in., or 1 mm, long) to live between sand particles to colonies that hang in clumps or chains as much as a 1.6 ft (0.5 m) across. The texture of colonies varies from soft and gelatinous to hard with calcium-containing skeletons. Freshwater bryozoans attach primarily to leaves, stems, and tree roots in shallow water. Marine bryozoans have a wide range of habitats, from coastal areas to great ocean depths, but are most common just below the tidemarks. Bryozoans feed by capturing plankton with their tentacles.

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Any of at least 12,000 species of small, spore-bearing land plants in the bryophyte division, found worldwide except in salt water. Mosses are simple and ancient plants that have survived nearly unchanged since the Permian Period (290–248 million years ago). Commonly found in moist, shady locations (e.g., forest floors), mosses may range in size from microscopic to more than 40 in. (1 m) long. They prevent erosion and release nutrients from the substrates on which they grow. The life cycle shows clear alternation of generations between the sexual gametophyte, with stemlike and leaflike structures that produce eggs and swimming sperm, and the sporophyte, a raised stalk that ends in a spore case (sporangium). Mosses also reproduce asexually by branching. The economically important genus Sphagnum forms peat. Many so-called mosses are not bryophytes, including Irish moss (a red form of algae); beard moss, Iceland moss, oak moss, and reindeer moss (all lichens); Spanish moss (a name used variously for a lichen or an air plant of the pineapple family); and club moss (an evergreen herb of the family Lycopodiaceae).

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Any of about 200 species of primitive vascular plants that constitute the genus Lycopodium (order Lycopodiales), mainly native to tropical mountains but also common in northern forests of both hemispheres. They are evergreen plants with needlelike leaves and, often, conelike clusters of small leaves (strobili; see cone), each with a kidney-shaped spore capsule at its base. Representative species include running pine, or stag's horn moss (L. clavatum), ground cedar (L. complanatum ‘flabelliforme'), shining club moss (L. lucidulum), fir club moss (L. selago), ground pine (L. obscurum), and alpine club moss (L. alpinum).

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Epiphyte (Tillandsia usneoides) in the pineapple family, found in southern North America, the West Indies, and Central and South America. It often hangs in large, beardlike, silvery-gray masses from trees and other plants and even on telephone poles, but it is not parasitic or structurally intertwined with its host. It takes in carbon dioxide and rainwater or dew for photosynthesis through tiny, hairlike scales that cover its threadlike leaves and long, threadlike stems. It absorbs nutrients from dust and solvents in rainwater, or from decaying organic matter around its aerial roots. Stalkless yellow flowers appear rarely. Spanish moss is sometimes used as a filler in packing boxes and upholstery, and around potted plants or floral arrangements.

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(born Oct. 24, 1904, New York, N.Y., U.S.—died Dec. 20, 1961, Palm Springs, Calif.) U.S. playwright and director. He wrote his first play at age 18 and achieved recognition when he collaborated with George S. Kaufman on Once in a Lifetime (1930). That success led to their popular comedies You Can't Take It with You (1936, Pulitzer Prize; film, 1938) and The Man Who Came to Dinner (1939; film, 1942). Hart wrote books for musicals for Irving Berlin and Cole Porter, wrote and directed plays such as Lady in the Dark (1941; film, 1944) and Winged Victory (1943; film, 1944), and directed the long-running musicals My Fair Lady (1956, Tony Award) and Camelot (1960).

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(born Oct. 24, 1904, New York, N.Y., U.S.—died Dec. 20, 1961, Palm Springs, Calif.) U.S. playwright and director. He wrote his first play at age 18 and achieved recognition when he collaborated with George S. Kaufman on Once in a Lifetime (1930). That success led to their popular comedies You Can't Take It with You (1936, Pulitzer Prize; film, 1938) and The Man Who Came to Dinner (1939; film, 1942). Hart wrote books for musicals for Irving Berlin and Cole Porter, wrote and directed plays such as Lady in the Dark (1941; film, 1944) and Winged Victory (1943; film, 1944), and directed the long-running musicals My Fair Lady (1956, Tony Award) and Camelot (1960).

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