Black Alder
Encyclopedia
Alnus glutinosa is an alder
native to most of Europe
, including all of the British Isles
and Fennoscandia
and locally in southwest Asia
.
Alnus glutinosa is a tree
that thrives in moist soils, and grows under favourable circumstances to a height of 20–30 m, exceptionally up to 37 m, though often less. It is characterized by its 5–10 cm short-stalked rounded leaves
6–12 cm long, becoming wedge-shaped at the base and with a slightly toothed margin. When young they are somewhat glutinous, whence the specific name, becoming later a glossy dark green. As with some other plants, growing near water it keeps its leaves longer than do trees in drier situations. The glossy green foliage lasts after other trees have put on the red or brown of autumn, which renders it valuable for landscape effect. As the Latin name glutinosa implies, the buds and young leaves are slightly sticky with a resin
ous gum.
There are four subspecies
:
The species is monoecious
. Flowers are wind-pollinated catkin
s: the slender cylindrical male catkin
s are pendulous, reddish in colour and 5–10 cm long; the female are smaller, 2 cm in length and dark brown to black in colour, hard, somewhat woody, and superficially similar to some conifer cones. When the small winged seeds have been scattered the ripe, woody, blackish cones remain, often lasting through the winter. The alder is readily propagated by seeds, but throws up root suckers abundantly.
alni, which forms nodules on the tree's root
s. This nitrogen-fixing bacterium absorbs nitrogen from the environment and fixes it into a form available to the tree. In return, the bacterium receives carbon which is produced by the tree through photosynthesis
. This relationship, which improves the fertility of the soil environment, has established A. glutinosa as an important pioneer species
in ecological succession
.
A. glutinosa is also a host to a wide variety of moss
and lichen
. Some common species found on A. glutinosa include: Tree Lungwort (Lobaria pulmonaria
), Stenocybe pullatula, and Menneguzzia terebrata.
, a recently evolved species of Phytophthora
probably of hybrid origin. This is causing extensive mortality in some parts of Europe.
. The supports of the Rialto at Venice
, and many buildings at Amsterdam
, are of Alder wood. It is also the traditional wood burnt to produce smoked fish and other smoked foods, though in some areas other woods are more often used now. Furniture is sometimes made from the wood, as were clogs
, and it supplies excellent charcoal for gunpowder. The bark is astringent; it is used for tanning
and dye
ing. Alnus glutinosa is also cultivated and locally naturalised
in eastern North America
.
Seeds of Alnus glutinosa contains hirsutanonol, oregonin and genkwanin
.
, a quick grower it responds well to pruning but branches can be a bit coarse and leaf size not reducing as well as the Italian Alder leaves do..
Alder
Alder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...
native to most of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, including all of the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
and Fennoscandia
Fennoscandia
Fennoscandia and Fenno-Scandinavia are geographic and geological terms used to describe the Scandinavian Peninsula, the Kola Peninsula, Karelia and Finland...
and locally in southwest Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
that thrives in moist soils, and grows under favourable circumstances to a height of 20–30 m, exceptionally up to 37 m, though often less. It is characterized by its 5–10 cm short-stalked rounded leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
6–12 cm long, becoming wedge-shaped at the base and with a slightly toothed margin. When young they are somewhat glutinous, whence the specific name, becoming later a glossy dark green. As with some other plants, growing near water it keeps its leaves longer than do trees in drier situations. The glossy green foliage lasts after other trees have put on the red or brown of autumn, which renders it valuable for landscape effect. As the Latin name glutinosa implies, the buds and young leaves are slightly sticky with a resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
ous gum.
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
:
- Alnus glutinosa subsp. glutinosa - Europe
- Alnus glutinosa subsp. barbata - Northern AnatoliaAnatoliaAnatolia is a geographic and historical term denoting the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey...
(RizeRizeRize is the capital of Rize Province, in northeast Turkey, on the Black Sea coast.-Etymology:The name comes from Greek or Ριζαίον , meaning "mountain slopes". In modern times, its name in Greek was usually Ριζούντα . Its Latin forms are Rhizus and Rhizaeum...
, TrabzonTrabzonTrabzon is a city on the Black Sea coast of north-eastern Turkey and the capital of Trabzon Province. Trabzon, located on the historical Silk Road, became a melting pot of religions, languages and culture for centuries and a trade gateway to Iran in the southeast and the Caucasus to the northeast...
, ArtvinArtvin-History:See Artvin Province for the history of the region.-Places of interest:* Artvin or Livana castle, built in 937There are a number of Ottoman Empire houses and public buildings including:* Salih Bey mosque, built in 1792...
); northern IranIranIran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia... - Alnus glutinosa subsp. antitaurica - Southern Anatolia, rare
- Alnus glutinosa subsp. betuloides - Eastern Anatolia.
The species is monoecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
. Flowers are wind-pollinated catkin
Catkin
A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated but sometimes insect pollinated . They contain many, usually unisexual flowers, arranged closely along a central stem which is often drooping...
s: the slender cylindrical male catkin
Catkin
A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated but sometimes insect pollinated . They contain many, usually unisexual flowers, arranged closely along a central stem which is often drooping...
s are pendulous, reddish in colour and 5–10 cm long; the female are smaller, 2 cm in length and dark brown to black in colour, hard, somewhat woody, and superficially similar to some conifer cones. When the small winged seeds have been scattered the ripe, woody, blackish cones remain, often lasting through the winter. The alder is readily propagated by seeds, but throws up root suckers abundantly.
Important ecological relationships
Alnus glutinosa is most noted for the symbiotic relationship with the bacterium FrankiaFrankia
Frankia is a genus of nitrogen fixing, filamentous bacteria that live in symbiosis with actinorhizal plants, similar to the Rhizobia bacteria that are found in the root nodules of legumes in the Fabaceae family. Bacteria of this genus also form root nodules.The genus Frankia was originally named by...
alni, which forms nodules on the tree's root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s. This nitrogen-fixing bacterium absorbs nitrogen from the environment and fixes it into a form available to the tree. In return, the bacterium receives carbon which is produced by the tree through photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
. This relationship, which improves the fertility of the soil environment, has established A. glutinosa as an important pioneer species
Pioneer species
Pioneer species are species which colonize previously uncolonized land, usually leading to ecological succession. They are the first organisms to start the chain of events leading to a livable biosphere or ecosystem...
in ecological succession
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
.
A. glutinosa is also a host to a wide variety of moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
and lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
. Some common species found on A. glutinosa include: Tree Lungwort (Lobaria pulmonaria
Lobaria pulmonaria
Lobaria pulmonaria is a large epiphytic lichen consisting of an ascomycete fungus and a green algal partner living together in a symbiotic relationship with a cyanobacterium—a symbiosis involving members of three kingdoms of organisms...
), Stenocybe pullatula, and Menneguzzia terebrata.
Diseases
Alnus glutinosa is susceptible to Phytophthora alniPhytophthora alni
Phytophthora alni is an oomycete plant pathogen that causes causes lethal root and collar rot in alders. It is widespread across Europe and has recently been found in North America. This species is believed to have originated relatively recently....
, a recently evolved species of Phytophthora
Phytophthora
Phytophthora is a genus of plant-damaging Oomycetes , whose member species are capable of causing enormous economic losses on crops worldwide, as well as environmental damage in natural ecosystems. The genus was first described by Heinrich Anton de Bary in 1875...
probably of hybrid origin. This is causing extensive mortality in some parts of Europe.
Uses
It is important as coppice-wood on marshy ground. The wood is soft, white when first cut and turning to pale red; the knots are beautifully mottled. Under water the wood is very durable, and it is therefore used for pilesDeep foundation
A deep foundation is a type of foundation distinguished from shallow foundations by the depth they are embedded into the ground. There are many reasons a geotechnical engineer would recommend a deep foundation over a shallow foundation, but some of the common reasons are very large design loads, a...
. The supports of the Rialto at Venice
Venice
Venice is a city in northern Italy which is renowned for the beauty of its setting, its architecture and its artworks. It is the capital of the Veneto region...
, and many buildings at Amsterdam
Amsterdam
Amsterdam is the largest city and the capital of the Netherlands. The current position of Amsterdam as capital city of the Kingdom of the Netherlands is governed by the constitution of August 24, 1815 and its successors. Amsterdam has a population of 783,364 within city limits, an urban population...
, are of Alder wood. It is also the traditional wood burnt to produce smoked fish and other smoked foods, though in some areas other woods are more often used now. Furniture is sometimes made from the wood, as were clogs
Clog (shoe)
A clog is a type of footwear made in part or completely from wood.The Oxford English Dictionary defines a clog as a "thick piece of wood", and later as a "wooden soled overshoe" and a "shoe with a thick wooden sole"....
, and it supplies excellent charcoal for gunpowder. The bark is astringent; it is used for tanning
Tanning
Tanning is the making of leather from the skins of animals which does not easily decompose. Traditionally, tanning used tannin, an acidic chemical compound from which the tanning process draws its name . Coloring may occur during tanning...
and dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
ing. Alnus glutinosa is also cultivated and locally naturalised
Naturalisation (biology)
In biology, naturalisation is any process by which a non-native organism spreads into the wild and its reproduction is sufficient to maintain its population. Such populations are said to be naturalised....
in eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Seeds of Alnus glutinosa contains hirsutanonol, oregonin and genkwanin
Genkwanin
Genkwanin is a O-methylated flavone, a type of flavonoid. It can be found in the seeds of Alnus glutinosa....
.
Bonsai
The Common Alder makes a large BonsaiBonsai
is a Japanese art form using miniature trees grown in containers. Similar practices exist in other cultures, including the Chinese tradition of penjing from which the art originated, and the miniature living landscapes of Vietnamese hòn non bộ...
, a quick grower it responds well to pruning but branches can be a bit coarse and leaf size not reducing as well as the Italian Alder leaves do..