soda ash: see sodium carbonate.

prickly ash, name for two deciduous shrubs or small trees (Zanthoxylum americanum and Z. clava-herculis) of the family Rutaceae (rue family). They are native to E North America and have prickly twigs and foliage similar to that of the unrelated ash tree. A pungent aromatic principle in the bark has been used as a home remedy for various ailments including rheumatism and toothaches (hence the local name toothache tree). Z. clava-herculis, of more southerly distribution, is also known as Hercules'-club. Both Hercules'-club and prickly ash are names sometimes used for an unrelated plant of the family Araliaceae (ginseng family). Other Zanthoxylum species are the sources of Sichuan and Sansho peppercorns (Z. simulans and Z. piperitum, respectively) and of satinwood (Z. flavum). Prickly ash of the genus Zanthoxylum is classified in the division Magnoliophyta, class Magnoliopsida, order Sapindales, family Rutaceae. The family Araliaceae belongs to the order Apiales.

pearl ash: see potassium carbonate.

mountain ash, name for any species of the genus Sorbus of the family Rosaceae (rose family), hardy ornamental trees and shrubs native to the Northern Hemisphere, not related to the true ashes. They are deciduous and bear flat-topped clusters of white flowers followed by orange or brilliant red berrylike fruits, for which they are widely cultivated as ornamentals. The astringent pome fruits are often used in domestic remedies. Of native kinds, the most common is the American mountain ash (S. americana), ranging from Newfoundland to North Carolina. Introduced species are often cultivated, especially the common European mountain ash or rowan tree (S. aucuparia). This tree is one of the most revered plants in the folklore of the Old World. It warded off evil influences and was "Thor's helper"; bits of the wood were thought to avert almost any disaster. Mountain ash is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

ash, in botany, any plant of the genus Fraxinus of the family Oleaceae (olive family), trees and shrubs mainly of north temperate regions. The ashes are characterized by small clusters of greenish flowers and by fruits with long "wings" to aid in wind dispersal. The most valuable of the species used for hardwood timber is the white ash (F. americana), ranging from Nova Scotia to Minnesota and Texas. Its strong, durable wood is used for sporting goods, furniture, tool handles, and oars. The bark of the blue ash (F. quadrangulata) yields a blue dye; the Mediterranean flowering ash (F. ornus) is the source of commercial manna. The name flowering ash is also applied to a shrubby species (F. cuspidata) of the California canyon chaparral and to the fringe tree (genus Chionanthus of the same family) of North America and China. The mountain ash and prickly ash are not true ashes. Ashes are classified in the division Magnoliophyta, class Magnoliopsida, order Scrophulariales, family Oleaceae.

ash, in chemistry, solid residue of combustion. The chemical composition of an ash depends on that of the substance burned. Wood ash contains metal carbonates (e.g., potassium carbonate) and oxides formed from metals originally compounded in the wood. Coal ash usually has a high content of minerals and is sometimes contaminated with rock; during combustion the mineral matter may become partially fused, forming cinders or clinker. Bone ash is largely made up of calcium phosphate. Seaweed ash (called kelp or varec) contains sodium carbonate, potassium carbonate, and iodine that can be extracted. Fly ash is very fine ash produced during the combustion of many materials.

Mountain Ash, Welsh Aberpennar, town (1981 pop. 26,231), Rhondda Cynon Taff, S Wales. A former mining community, it depended upon the great coal mines nearby, which were developed in the 19th cent. A pavilion was built in 1906 to house the annual Welsh arts festival, the eisteddfod.

Madinat ash Shab, town, SW Yemen, just N of Aden. Formerly called al-Ittihad, it was built in the 1960s as the federal capital of the Federation of South Arabia. From 1967 to 1970 it was, together with Aden, the capital of South Yemen.

Ash Wednesday, in the Western Church, the first day of Lent, being the seventh Wednesday before Easter. On this day ashes are placed on the foreheads of the faithful to remind them of death, of the sorrow they should feel for their sins, and of the necessity of changing their lives. The practice, which dates from the early Middle Ages, is common among Roman Catholics, Anglicans and Episcopalians, and many Lutherans; it was also adopted by some Methodists and Presbyterians in the 1990s.

Ahmad bin Muhammad al-Barmaki al-Irbili ash-Shafii: see Ibn Khalikan.

Any of several shrubs or trees of the genus Sorbus, in the rose family, native to the Northern Hemisphere. They are widely cultivated as ornamentals for their white flower clusters and bright-orange fruits. Most noteworthy are the handsome American mountain ash, or dogberry (S. americana), and European mountain ash (S. aucuparia), also called rowan, or quickbeam. The European species grows to 60 ft (18 m), twice as high as the American species.

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Hardy and fast-growing tree (Acer negundo), also called ash-leaved maple, of the maple family, native to the central and eastern U.S. Its compound leaves (rare among maples) consist of three, five, or seven coarsely toothed leaflets. The single seed is borne in a samara (dry, winged fruit). Because of its rapid growth and its drought resistance, it was widely planted for shade by early settlers in the prairie regions of the U.S. Maple syrup and sugar are sometimes obtained from the box elder. Its wood is used for crates, furniture, paper pulp, and charcoal.

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or ash cone

Deposit around a volcanic vent, formed by rock fragments or cinders that accumulate and gradually build a conical hill with a bowl-shaped crater at the top. Cinder cones develop from explosive eruptions of lavas and are often found along the flanks of shield (gently sloping) volcanoes. Lava flows may break out of the cone, or they may flow from under the cone through tunnels. Cinder cones are common in nearly all volcanic areas. Although they are composed of loose or only moderately consolidated cinder, many are surprisingly long-lasting, because rain falling on them sinks into the highly permeable cinders instead of running off down their slopes and eroding them.

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Any tree of the genus Fraxinus, in the olive family. The genus includes about 70 species of trees and shrubs found mostly in the Northern Hemisphere. The U.S. boasts 18 species of ash, 5 of which furnish most of the ash cut as lumber. Most important are the white ash (F. americana) and the green ash (F. pennsylvanica), which yield wood that is stiff, strong, and resilient, yet lightweight. This “white ash” is used for baseball bats, hockey sticks, paddles and oars, tennis and other racket frames, and the handles of agricultural tools. Black ash (F. nigra), blue ash (F. quadrangulata), and Oregon ash (F. latifolia) produce wood of comparable quality that is used for many more purposes, including furniture, interior paneling, and barrels.

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