Alder

/ahl'deuhr/; Ger. /ahl"deuhrdd/, n.
Kurt /kerrt/; Ger. /koorddt/, 1902-58, German chemist: Nobel prize 1950.

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Any of about 30 species of ornamental shrubs and trees in the genus Alnus, of the birch family, found throughout the Northern Hemisphere and western South America on cool, wet sites.

Alders are distinguished from birches by their usually stalked winter buds and by cones that remain on the branches after the small, winged nutlets are released. Alders have scaly bark, oval leaves that fall without changing colour, and separate male and female flowers (catkins) borne on the same tree. Some familiar North American alders are the red alder (A. rubra or A. oregona); the white, or Sierra, alder (A. rhombifolia); and the speckled alder (A. rugosa). Alder wood is fine-textured and durable, even under water; it is useful for furniture, cabinetry, and lathe work and in charcoal manufacture and millwork. Alders' spreading root systems and tolerance of moist soils lend them to planting on stream banks for flood and erosion control.

Alder (Alnus glutinosa)

Earl L. Kubis
Root Resources

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plant
 any of about 30 species of ornamental shrubs and trees constituting the genus Alnus, in the birch family (Betulaceae), distributed throughout the Northern Hemisphere and western South America on cool, wet sites at elevations up to 2,500 m (8,200 feet).

      An alder may be distinguished from a birch by its usually stalked winter buds and by cones that remain on the branches after the small, winged nutlets are released. The scaly bark is grayish brown in some species and almost white in others. The oval leaves are alternate, serrate, and often shallowly lobed; sticky on unfolding but glossy when mature, they fall without changing colour. Male and female flowers are borne in separate catkins on the same tree; they form during the summer and usually blossom the following spring before the leaves open.

      Familiar North American alders are the red alder (A. rubra, or A. oregona), a tall tree whose leaves have rusty hairs on their lower surfaces; the white, or Sierra, alder (A. rhombifolia), an early-flowering tree with orange-red twigs and buds; the speckled alder (A. rugosa), a small tree with conspicuous whitish, wartlike, porous markings, or lenticels; the aromatic-leaved American green alder (A. crispa or A. mitchelliana); the closely related but taller Sitka alder (A. sinuata); and the mountain, or thinleaf, alder (A. tenuifolia), a shrubby tree with yellow or orange-brown midribs on its leaves and a domelike crown of pendulous branches.

      The European alder (A. glutinosa), sometimes known as black alder for its dark bark and cones, is widespread throughout Eurasia and is cultivated in several varieties in North America. The name black alder is also applied to winterberry, a type of holly. The green alder (A. viridis), a European shrub, has sharply pointed, bright-green leaves. The white alder (A. incana) includes several varieties useful as an ornamental.

      Alders are practically immune to diseases other than fungal attacks. Usually propagated by seed, they may also be cultivated from cuttings or suckers.

      Alder wood, pale yellow to reddish brown, is fine-textured and durable, even under water; it is useful for furniture, cabinetry, turnery, and in charcoal manufacture and millwork. Red and European alders are important timber trees. European, Italian, Japanese, Manchurian, speckled, and seaside alders are popular ornamentals. Because of their spreading root systems and tolerance of moist soils, alders are often planted on stream banks for flood control and the prevention of erosion. They are among the first woody plants to appear in denuded areas; although short-lived, they prepare the soil for more enduring trees by increasing its organic matter and nitrogen content.

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Universalium. 2010.

Look at other dictionaries:

  • Alder — ist der Familienname folgender Personen: Albert Alder (1888–1980), Schweizer Mediziner Bernie Alder (* 1925), US amerikanischer Physiker Charles Robert Alder Wright (1844–1894) englischer Chemiker Christian Alder (* 1978), deutscher… …   Deutsch Wikipedia

  • Alder — Al der ([add]l d[ e]r), n. [OE. aldir, aller, fr. AS. alr, aler, alor, akin to D. els, G. erle, Icel. erlir, erli, Swed. al, Dan. elle, el, L. alnus, and E. elm.] (Bot.) A tree, usually growing in moist land, and belonging to the genus {Alnus}.… …   The Collaborative International Dictionary of English

  • Alder — Alder, MT U.S. Census Designated Place in Montana Population (2000): 116 Housing Units (2000): 69 Land area (2000): 2.013323 sq. miles (5.214482 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 2.013323 sq. miles …   StarDict's U.S. Gazetteer Places

  • Alder, MT — U.S. Census Designated Place in Montana Population (2000): 116 Housing Units (2000): 69 Land area (2000): 2.013323 sq. miles (5.214482 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 2.013323 sq. miles (5.214482 …   StarDict's U.S. Gazetteer Places

  • alder- — variant of aller gen. pl. of all, used in comb. as alder best, alder liefest: see all D 3 …   Useful english dictionary

  • alder — (n.) tree related to the birch, O.E. alor alder (with intrusive d added 14c.; the historical form aller survived until 18c. in literary English and persists in dialects, e.g. Lancashire owler, which is partly from Norse), from P.Gmc. *aliso (Cf.… …   Etymology dictionary

  • Alder — (izg. àlder), Kurt (1902 1958) DEFINICIJA njemački kemičar, za razvoj Diels Alderove reakcije (široko upotrebljavane metode sintetiziranja cikličkih organskih tvari); Nobelova nagrada za kemiju 1950 (s O. Dielsom) …   Hrvatski jezični portal

  • alder — [ôl′dər] n. [ME alder, aller < OE alor, aler < IE base * el : see ELM] any of a small group of rapidly growing trees and shrubs (genus Alnus) of the birch family, having toothed leaves and catkins, and growing in cool, moist soil in… …   English World dictionary

  • Alder — Al der ([add]l d[ e]r), Aller Al ler ([add]l l[ e]r), a. [From ealra, alra, gen. pl. of AS. eal. The d is excrescent.] Of all; used in composition; as, alderbest, best of all, alderwisest, wisest of all. [Obs.] Chaucer. [1913 Webster] …   The Collaborative International Dictionary of English

  • Alder — Alder, Kurt …   Enciclopedia Universal

  • alder — ► NOUN ▪ a tree of the birch family, which bears catkins and has toothed leaves. ORIGIN Old English …   English terms dictionary

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