''Alnus incana'', the grey alder or speckled alder, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
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 common sight in swamps and wetlands. It is easily distinguished by its small cones, speckled bark and broad leaves.
Description
![Alnus incana var](https://upload.wikimedia.org/wikipedia/commons/7/77/Alnus_incana_var._tenuifolia_4.jpg)
It is a small- to medium-sized tree tall with smooth grey bark even in old age, its life span being a maximum of 60 to 100 years. The
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are matte green, ovoid, long and broad. The flowers are
catkin
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...
s, appearing early in spring before the leaves emerge, the male catkins pendulous and long, the female catkins long and one cm broad when mature in late autumn. The seeds are small, long, and light brown with a narrow encircling wing. The grey alder has a shallow root system, and is marked not only by vigorous production of stump suckers, but also by
root suckers, especially in the northern parts of its range. The wood resembles that of the
black alder Black alder is a common name for several plants and may refer to:
*''Alnus glutinosa
''Alnus glutinosa'', the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, nativ ...
(''Alnus glutinosa''), but is somewhat paler and of little economic value.
Subspecies
There are four to six subspecies, some treated as separate species by some authors:
* ''Alnus incana'' subsp. ''incana''; grey alder — Northern
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
and northwestern
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
, and central and southern Europe in mountains, mainly in the regions of the
Alps
The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...
,
Carpathians
The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Ural Mountains, Urals at and the Scandinavian Mountains at . The ...
and the
Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...
* ''Alnus incana'' subsp. ''hirsuta'' (=''A. hirsuta'' ); Manchurian alder — In mountains of
Northeast Asia
Northeast Asia or Northeastern Asia is a geographical subregion of Asia; its northeastern landmass and islands are bounded by the Pacific Ocean.
The term Northeast Asia was popularized during the 1930s by American historian and political scienti ...
and
Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
* ''Alnus incana'' subsp. ''kolaensis'' — Subarctic northeast
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
* ''Alnus incana'' subsp. ''oblongifolia'' (=''
Alnus oblongifolia
''Alnus oblongifolia'' (Arizona alder) is a large alder growing up to , from the southwestern United States and northern Sonora, Mexico. It grows across Arizona into western New Mexico mountain ranges. In central Arizona its range extends across ...
''); Arizona alder —
Madrean Sky Islands
The Madrean Sky Islands are enclaves of Madrean pine–oak woodlands, found at higher elevations in a complex of small mountain ranges in southern and southeastern Arizona, southwestern New Mexico, and northwestern Mexico. The sky islands are sur ...
of southwestern
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, in
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
,
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
, and Northwestern Mexico
* ''Alnus incana'' subsp. ''rugosa'' (=''A. rugosa'' ); speckled alder — Much of
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
below the
tree line
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowp ...
, and the
Northeastern United States
The Northeastern United States, also referred to as the Northeast, the East Coast, or the American Northeast, is a geographic region of the United States. It is located on the Atlantic coast of North America, with Canada to its north, the Southe ...
* ''Alnus incana'' subsp. ''tenuifolia'' (=''A. tenuifolia'' ); mountain alder, or thinleaf alder — Western North America, including
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
to
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
and
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
; the roots have
nitrogen-fixing
Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmos ...
nodules.
Alnus incana ssp incana range map 1.png, ''A. incana'' subsp. ''incana'' range
Alnus incana ssp rugosa range map 1.png, ''A. incana'' subsp. ''rugosa'' range
Alnus incana ssp tenuifolia range map 1.png, ''A. incana'' subsp. ''tenuifolia'' range
Ecology
''Alnus incana'' is a light-demanding, fast-growing tree that grows well on poorer soils. In central Europe, it is a colonist of
alluvial
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...
land alongside mountain brooks and streams, occurring at elevations up to . However, it does not require moist soil, and will also colonize screes and shallow stony slopes. In the northern part of its range, it is a common tree species at sea level in forests, abandoned fields and on lakeshores. Several species of
Lepidoptera
Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...
use grey
alder as a food plant for their
caterpillar
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...
s. In the
boreal forest
Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, ...
area of Canada, ''A. incana'' is often associated with
black spruce
''Picea mariana'', the black spruce, is a North American species of spruce tree in the pine family. It is widespread across Canada, found in all 10 provinces and all 3 territories. It is the official tree of the province of Newfoundland and Labra ...
in the forest type termed black spruce–speckled alder. The larvae of the
alder woolly sawfly sometimes cause considerable defoliation to the grey alder.
''A. rugosa'' provides cover for wildlife, is browsed by deer and moose, and the seeds are eaten by birds.
Chemistry
Pedunculagin
Pedunculagin is an ellagitannin. It is formed from casuarictin via the loss of a gallate group.
Natural occurrence
Pedunculagin is found in plants in orders in the clade Rosidae. It can be found the pericarp of pomegranates (''Punica granatum' ...
is an ellagitannin found in the Manchurian alder (''A. hirsuta var. microphylla'').
Uses
The tree is cultivated in parks and gardens. The cultivar 'Aurea', with green-gold leaves, has gained the
Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...
's
Award of Garden Merit
The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions.
History
The Award of Garden Merit ...
.
It is sometimes used in
afforestation
Afforestation is the establishment of a forest or stand of trees (forestation) in an area where there was no previous tree cover. Many government and non-governmental organizations directly engage in afforestation programs to create forests a ...
and
agroforestry
Agroforestry is a land use management system in which trees or shrubs are grown around or among crops or pastureland. Trees produce a wide range of useful and marketable products from fruits/nuts, medicines, wood products, etc. This intentional ...
in non-fertile or wet soils which it enriches by means of
nitrogen fixing
Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the Atmosphere of Earth, air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but al ...
bacteria in its root nodules.
Alder is an excellent tree for coppicing and pollarding. Its cut branches may be fed to browsing livestock such as cows and goats, then used for kindling, firewood, or light construction - while root systems fertilize adjacent agricultural plots via nitrogen fixation.
The
Zuni people
The Zuni ( zun, A:shiwi; formerly spelled ''Zuñi'') are Native American Pueblo peoples native to the Zuni River valley. The Zuni are a Federally recognized tribe and most live in the Pueblo of Zuni on the Zuni River, a tributary of the Lit ...
use the bark of the ''tenuifolia'' subspecies to dye deerskin reddish brown.
The
Ho-Chunk people
The Ho-Chunk, also known as Hoocągra or Winnebago (referred to as ''Hotúŋe'' in the neighboring indigenous Iowa-Otoe language), are a Siouan-speaking Native American people whose historic territory includes parts of Wisconsin, Minnesota, Iow ...
eat the bark of the ''rugosa'' subspecies when their stomachs are "sour" or upset.
Its wood and bark are used in smoking meat, particularly fish and duck.
References
Further reading
*
*
*
*
{{Taxonbar, from=Q157641
incana
The Socotra warbler (''Incana incana'') is a species of bird in the family Cisticolidae. It is monotypic within the genus ''Incana''. It is endemic to Socotra. Its natural habitats are subtropical or tropical dry shrubland and subtropical or tr ...
Trees of Europe
Trees of North America
Trees of Asia
Plant dyes
Plants described in 1753
Taxa named by Carl Linnaeus