Alders are trees of the genus Alnus in the birch family Betulaceae. The genus includes about 35 species [2] of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species extending into Central America, as well as the northern and southern Andes. [1]

Alnus glutinosa, the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa.

Alder is the common name for about 30 kinds of trees and shrubs of the Alnus genus. They are a part of the birch family (Betulaceae). Most of them are smaller in size. Leaves are mostly deciduous, only very few alders are evergreen. Alder trees are found in all parts of the northern hemisphere and they are often found on poor and/or wet soil.

Alnus serrulata, the hazel alder or smooth alder, is a thicket-forming shrub in the family Betulaceae. It is native to eastern North America and can be found from western Nova Scotia and southern New Brunswick south to Florida and Texas.

Alnus rubra is the largest species of alder in North America and one of the largest in the world, reaching heights of 20 to 30 metres (66 to 98 ft). The official tallest red alder (as of 1979) stands 32 m (105 ft) tall in Clatsop County, Oregon (US). [7] . The trunks range from 25 to 50 centimetres (10 to 19⁄2 in) in diameter. [8] .

Alnus alnobetula is a common tree widespread across much of Europe, Asia, and North America. [2] . Many sources refer to it as Alnus viridis, the green alder, but botanically this is considered an illegitimate name synonymous with Alnus alnobetula subsp. fruticosa. [3]

Alnus incana, the grey alder, tag alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners and is a …

2024年12月28日 · alder, (genus Alnus), genus of about 30 species of ornamental shrubs and trees in the birch family (Betulaceae). Alders are distributed throughout the Northern Hemisphere and in parts of western South America on cool wet sites at …

2025年1月2日 · Grey alder, Alnus incana. Inherited from Middle English aldre, alder, aller, from Old English alor, from Proto-West Germanic *aluʀu, from Proto-Germanic *aluz, *alusō, *alizō, *alisō. alder (plural alders) Any of several trees or shrubs …

Alnus acuminata grows at altitudes between 1,500 and 3,200 metres (4,900 and 10,500 ft) in the mountain ranges in tropical Central and South America from Mexico to northern Argentina. It mostly grows on areas with 1000–3000 mm of rainfall, on slopes and valleys. It tolerates poor soils and acid conditions, but prefers silt or sandy silt soils. [10]