Alder is the common name of a genus of flowering plants (Alnus) belonging to the birch family Betulaceae. The genus comprises about 35 species 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.
The common name alder evolved from Old English alor, which in turn is derived from Proto-Germanic root aliso. The generic name Alnus is the equivalent Latin name. Both the Latin and the Germanic words derive from the Proto-Indo-European root el-, meaning "red" or "brown", which is also a root for the English words elk and another tree: elm, a tree distantly related to the alders.
With a few exceptions, alders are deciduous, and the leaves are alternate, simple, and serrated. The flowers are catkins with elongate male catkins on the same plant as shorter female catkins, often before leaves appear; they are mainly wind-pollinated, but also visited by bees to a small extent. These trees differ from the birches (Betula, another genus in the family) in that the female catkins are woody and do not disintegrate at maturity, opening to release the seeds in a similar manner to many conifer cones.
The largest species are red alder (A. rubra) on the west coast of North America, and black alder (A. glutinosa), native to most of Europe and widely introduced elsewhere, both reaching over 30 m. By contrast, the widespread Alnus viridis (green alder) is rarely more than a 5-m-tall shrub.
Alders are commonly found near streams, rivers, and wetlands. In the Pacific Northwest of North America, the white alder (Alnus rhombifolia) unlike other northwest alders, has an affinity for warm, dry climates, where it grows along watercourses, such as along the lower Columbia River east of the Cascades and the Snake River, including Hells Canyon.
Alder leaves and sometimes catkins are used as food by numerous butterflies and moths.
A. glutinosa and A. viridis are classed as environmental weeds in New Zealand. Alder leaves and especially the roots are important to the ecosystem because they enrich the soil with nitrogen and other nutrients.
Alder is particularly noted for its important symbiotic relationship with Frankia alni, an actinomycete, filamentous, nitrogen-fixing bacterium. This bacterium is found in root nodules, which may be as large as a human fist, with many small lobes, and light brown in colour. The bacterium absorbs nitrogen from the air and makes it available to the tree. Alder, in turn, provides the bacterium with sugars, which it produces through photosynthesis. As a result of this mutually beneficial relationship, alder improves the fertility of the soil where it grows, and as a pioneer species, it helps provide additional nitrogen for the successional species which follow.
Because of its abundance, red alder delivers large amounts of nitrogen to enrich forest soils. Red alder stands have been found to supply between 120 and 290 pounds of nitrogen per acre (130 to 320 kg per ha) annually to the soil. From Alaska to Oregon, Alnus viridis subsp. sinuata (A. sinuata, Sitka Alder or Slide Alder), characteristically pioneer fresh, gravelly sites at the foot of retreating glaciers. Studies show that Sitka alder, a more shrubby variety of alder, adds nitrogen to the soil at an average of 55 pounds per acre (60 per ha) per year, helping convert the sterile glacial terrain to soil capable of supporting a conifer forest. Alders are common among the first species to colonize disturbed areas from floods, windstorms, fires, landslides, etc. Alder groves themselves often serve as natural firebreaks since these broad-leaved trees are much less flammable than conifers. Their foliage and leaf litter does not carry a fire well, and their thin bark is sufficiently resistant to protect them from light surface fires. In addition, the light weight of alder seeds (650,000 per pound, or 1.5 million per kg) allows for easy dispersal by the wind. Although it outgrows coastal Douglas-fir for the first 25 years, it is very shade intolerant and seldom lives more than 100 years. Red alder is the Pacific Northwest's largest alder and the most plentiful and commercially important broad-leaved tree in the coastal Northwest. Groves of red alder 10 to 20 inches (25 to 50 cm) in diameter intermingle with young Douglas-fir forests west of the Cascades, attaining a maximum height of 100 to 110 feet (30 to 33 m) in about sixty years and then lose vigor as heart rot sets in. Alders largely help create conditions favorable for giant conifers that replace them.
Alder roots are parasitized by northern groundcone.
The catkins of some alder species have a degree of edibility, and may be rich in protein. Reported to have a bitter and unpleasant taste, they are more useful for survival purposes. The wood of certain alder species is often used to smoke various food items such as coffee, salmon and other seafood.
Most of the pilings that form the foundation of Venice were made from alder trees.
Alder bark contains the anti-inflammatory salicin, which is metabolized into salicylic acid in the body. Some Native American cultures use red alder bark (Alnus rubra) to treat poison oak, insect bites, and skin irritations. Blackfeet Indians have traditionally used an infusion made from the bark of red alder to treat lymphatic disorders and tuberculosis. Recent clinical studies have verified that red alder contains betulin and lupeol, compounds shown to be effective against a variety of tumors.
The inner bark of the alder, as well as red osier dogwood, or chokecherry, is used by some Indigenous peoples of the Americas in smoking mixtures, known as kinnikinnick, to improve the taste of the bearberry leaf.
Alder is illustrated in the coat of arms for the Austrian town of Grossarl.
Electric guitars, most notably those manufactured by the Fender Musical Instruments Corporation, have been built with alder bodies since the 1950s. Alder is appreciated for its claimed tight and even balanced tone, especially when compared to mahogany, and has been adopted by many electric guitar manufacturers.
As a hardwood, alder is used in making furniture, cabinets, and other woodworking products. For example, in the television series Northern Exposure season 3 episode "Things Become Extinct" (1992), Native American Ira Wingfeather makes duck flutes out of alder tree branches while Ed Chigliak films.
A red dye can also be extracted from the outer bark, and a yellow dye from the inner bark.
The genus is divided into three subgenera:
Subgenus Alnus: Trees with stalked shoot buds, male and female catkins produced in autumn (fall) but stay closed over winter, pollinating in late winter or early spring, about 15–25 species, including:
Subgenus Clethropsis. Trees or shrubs with stalked shoot buds, male and female catkins produced in autumn (fall) and expanding and pollinating then, three species:
Subgenus Alnobetula. Shrubs with shoot buds not stalked, male and female catkins produced in late spring (after leaves appear) and expanding and pollinating then, one to four species:
Alder is a lunar impact crater that is located in the southern hemisphere on the far side of the Moon. It is located in the South Pole-Aitken basin, and lies to the southeast of the crater Von Kármán. Southeast of Alder is Bose, and to the south-southwest lies Boyle.
The inner wall of Alder is rough and slightly terraced, with the material scattered across the edges of the otherwise relatively flat interior floor. There are several low central ridges lying along a band from the midpoint toward the eastern rim. A small crater lies on the eastern inner slopes. The crater is otherwise free of significant impacts within the rim.
Alder is associated with the only area in the basin not dominated by the pyroxene rocks typical of lunar lowlands. This alder ejecta area is on spectrographic evidence instead principally anorthosite rock, typical of the lunar highlands.Alder Flats
Alder Flats is a hamlet in central Alberta, Canada within the County of Wetaskiwin No. 10. It is located 8 kilometres (5.0 mi) west of Highway 22 at the western terminus of Highway 13, approximately 120 kilometres (75 mi) southwest of Edmonton.Alder Grange Community and Technology School
Alder Grange School is a secondary school and sixth form located in the east Lancashire town of Rawtenstall, England.Alder Gulch
Alder Gulch (alternatively called Alder Creek) is a place in the Ruby River valley, in the U.S. state of Montana, where gold was discovered on May 26, 1863, by William Fairweather and a group of men including Barney Hughes, Thomas Cover, Henry Rodgers, Henry Edgar and Bill Sweeney who were returning to the gold fields of Grasshopper Creek, Bannack, Montana. They were on their way to Yellowstone Country from Bannack but were waylaid by a band of Crow Indians. After being ordered out of Crow hunting grounds, they crossed the East Slope of the Tobacco Root Mountains and camped for the night in Elk Park, where William "Bill" Fairweather and Henry Edgar discovered gold, while the remaining party was out hunting for meat. Agreeing to keep the new discovery quiet the group of miners returned to the town of Bannack for supplies. However, word leaked out about the new strike, and miners followed the Fairweather party out of town. The party stopped at the Point of Rocks, part way between Bannack and Alder Gulch, and established the Fairweather Mining District in a miners meeting. It was agreed that the discoverers were entitled to two claims and first choice. The first stampede of miners reached Alder Gulch June 6, 1863, and the population swelled to over 10,000 in less than 3 months. The "Fourteen Mile City" ran the length of the gulch, and included the towns of Junction City, Adobe Town, Nevada City, Central City, Virginia City, Montana, Bear Town, Highland, Pine Grove French Town, Hungry Hollow, and Summit. Upon arrival the miners lived in brush wickiups, dugouts and under overhanging rocks until cabins could be built. The first structure built in Virginia City was the Mechanical Bakery. Virginia City, and Nevada City were the centers of commerce during the height of the Alder Gulch gold rush. In the first year the area had over 10,000 people living there. Montana Territory was established in May 1864, and the first territorial capital was Bannock. The capital then moved to Virginia City, where it remained until 1875. The Alder Gulch diggings were the richest gold placer deposits ever discovered, and in three years $30,000,000 was taken from them, with $10,000,000 taken out in the first year. Nowadays, except during summertime, the streets of Virginia City are usually quiet and relatively few visitors find their way to the 16 ton granite monument that marks the spot of that incredible discovery of May 26, 1863.
Alder Gulch is named for the alder bushes that grew along the creek.Alder Hey Children's Hospital
Alder Hey Children's Hospital is a children's hospital and NHS foundation trust in West Derby, Liverpool, England. It is one of the largest children's hospitals in the United Kingdom, and one of several specialist hospitals within the Liverpool City Region, alongside the Royal Liverpool University Hospital, Liverpool Women's Hospital, Liverpool Heart and Chest Hospital, the Walton Centre, Mersey Regional Burns and Plastic Surgery Unit, and Clatterbridge Cancer Centre.Alder Springs, Fresno County, California
Alder Springs is an unincorporated community in Fresno County, California. It is located 5.5 miles (9 km) west-southwest of Shaver Lake Heights, at an elevation of 4426 feet (1349 m).Alder Valley
Alder Valley was a bus operator in South East England.Alnus glutinosa
Alnus glutinosa, the common alder, black alder, European alder or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils. It is a medium size, short-lived tree growing to a height of up to 30 metres (100 ft). It has short-stalked rounded leaves and separate male and female flower in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.
The common alder provides food and shelter to wildlife, with a number of insects, lichens and fungi being completely dependent on the tree. It is a pioneer species, colonising vacant land and forming mixed forests as other trees appear in its wake. Eventually common alder dies out of woodlands because the seedlings need more light than is available on the forest floor. Its more usual habitat is forest edges, swamps and riverside corridors. The timber has been used in underwater foundations and for manufacture into paper and fibreboard, for smoking foods, for joinery, turnery and carving. Products of the tree have been used in ethnobotany, providing folk remedies for various ailments, and research has shown that extracts of the seeds are active against pathogenic bacteria.Alnus incana
Alnus incana, the grey alder or speckled alder, is a species of alder with a wide range across the cooler parts of the Northern Hemisphere.Alnus rubra
Alnus rubra, the red alder,
is a deciduous broadleaf tree native to western North America (Alaska, Yukon, British Columbia, Washington, Oregon, California, Idaho and Montana).Ben Alder
Ben Alder (Gaelic: Beinn Eallair) is the highest mountain in the remote area of the Scottish Highlands between Loch Ericht and Glen Spean. The vast summit plateau is home of one of Britain's highest bodies of standing water, Lochan a' Garbh Coire. It is the 25th highest Munro, and due to its remote location, one of the less frequently visited. Situated 19 km from Dalwhinnie and 15 km from Corrour railway station, it is commonly climbed in a two-day expedition, usually taking in its lower neighbour, Beinn Bheoil. There are two bothies near to the mountain: Culra Lodge to the northeast and Ben Alder Cottage to the south, both potentially providing shelter for walkers in the area. Ben Alder Cottage is reputed to be haunted by the ghost of a ghillie who hanged himself from the rafters.
If a mountain bicycle is used on, or permission is obtained to drive on the track along the north west shore of Loch Ericht, Ben Alder is one of six Munros that a fit climber may be able to summit on a single late spring or early summer day.Berni Alder
Berni Julian Alder (born September 9, 1925) is an American physicist specialized in statistical mechanics, and a pioneer of numerical simulation in physics.Carr (landform)
A carr is a type of waterlogged wooded terrain that, typically, represents a succession stage between the original reedy swamp and the likely eventual formation of forest in a sub-maritime climate. The name derives from the Old Norse kjarr, meaning a swamp. The carr is one stage in a hydrosere: the progression of vegetation beginning from a terrain submerged by fresh water along a river or lake margin. In sub-maritime regions, it begins with reed-swamp. As the reeds decay, the soil surface eventually rises above the water, creating fens that allow vegetation such as sedge to grow. As this progression continues, riparian trees and bushes appear and a carr landscape is created – in effect a wooded fen in a waterlogged terrain. At this stage, overall, unlike the overwhelming acidity of decaying reeds, the pH is not too acidic and the soil is not too deficient in minerals, making a habitat for endemic and other wildlife. Characteristic trees include alder, willow and sallow.Colfax, California
Alden Grove, Alder Grove, Illinoistown, and Upper Corral) is a city in Placer County, California, at the crossroads of Interstate 80 and State Route 174. It is part of the Sacramento–Arden-Arcade–Roseville Metropolitan Statistical Area. The population was 1,963 at the 2010 census. The town is named in honor of U.S. Vice President Schuyler Colfax (1869–73), a bronze statue of whom stands at Railroad Street and Grass Valley Street. (This is the only known statue of Schuyler Colfax in the United States). Some of the town's notable features include the newly restored Southern Pacific Railroad colonnade-style depot (which houses the Colfax Museum and Chamber of Commerce) built in 1905, the downtown shops on Main Street, and Colfax High School, which serves a large surrounding area.Diels–Alder reaction
In organic chemistry, the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile (also spelled dieneophile), to form a substituted cyclohexene derivative. It is the prototypical example of a pericyclic reaction with a concerted mechanism. More specifically, it is classified as a thermally-allowed [4+2] cycloaddition with Woodward–Hoffmann symbol [π4s + π2s]. It was first described by Otto Diels and Kurt Alder in 1928. For the discovery of this reaction, they were awarded the Nobel Prize in Chemistry in 1950. Through the simultaneous construction of two new carbon–carbon bonds, the Diels–Alder reaction provides a reliable way to form six-membered rings with good control over the regio- and stereochemical outcomes. Consequently, it has served as a powerful and widely applied tool for the introduction of chemical complexity in the synthesis of natural products and new materials. The underlying concept has also been applied to π-systems involving heteroatoms, such as carbonyls and imines, which furnish the corresponding heterocycles; this variant is known as the hetero-Diels–Alder reaction. The reaction has also been generalized to other ring sizes, although none of these generalizations have matched the formation of six-membered rings in terms of scope or versatility. Because of the negative values of ΔH° and ΔS° for a typical Diels–Alder reaction, the microscopic reverse of a Diels–Alder reactions becomes favorable at high temperatures, although this is of synthetic importance for only a limited range of Diels-Alder adducts, generally with some special structural features; this reverse reaction is known as the retro-Diels–Alder reaction.Erlking
"Erlking" (German: Erlkönig, lit. 'alder-king') is a name used in German Romanticism for the figure of a spirit or "king of the fairies". It is usually assumed that the name is a derivation from the ellekonge (older elverkonge, i.e. "Elf-king") in Danish folklore. The name is first used by Johann Gottfried Herder in his ballad "Erlkönigs Tochter" (1778), an adaptation of the Danish Hr. Oluf han rider (1739), and was notably taken up by Johann Wolfgang von Goethe in his poem "Erlkönig" (1782), which was set in music by Schubert, among others. In English translations of Goethe's poem, the name is sometimes rendered as Erl-king.Kurt Alder
Kurt Alder (German: [ˈaldɐ]; 10 July 1902 – 20 June 1958) was a German chemist and Nobel laureate.River's Edge, Edmonton
River's Edge, briefly known as River Alder, is a future neighbourhood in west Edmonton, Alberta, Canada. Subdivision and development of the neighbourhood will be guided by the Riverview Neighbourhood 3 (River's Edge) Neighbourhood Structure Plan (NSP), which was adopted by Edmonton City Council on September 22, 2015. It is located within the Riverview area of Edmonton and was originally considered Riverview Neighbourhood 3 within the Riverview Area Structure Plan (ASP). River's Edge is bounded on the north by The Uplands, northeast by Anthony Henday Drive, east and south by the North Saskatchewan River valley, southwest by Grandisle, and west by Stillwater.The five future neighbourhoods in Riverview were originally named by Edmonton's Naming Committee on June 25, 2015, with Riverview Neighbourhood 3 being named River Alder. The developers of River Alder and two other adjacent future neighbourhoods subsequently appealed three of neighbourhood names to City Council's Executive Committee. The Executive Committee overturned the naming decisions for the three neighbourhoods and River Alder was renamed River's Edge.Stanley and Alder Carrs, Aldeby
Stanley and Alder Carrs, Aldeby is a 42.7-hectare (106-acre) biological Site of Special Scientific Interest east of Gillingham in Norfolk. It is part of the Broadland Ramsar site and Special Protection Area, and The Broads Special Area of Conservation.Most of this site is alder carr woodland next to the River Waveney, which is often flooded. It has a diverse insect fauna. There are also areas of open fen with plants including common reed, reed canary grass and hemp-agrimony.The site is private land with no public access.
Sources of tannins