''Frangula alnus'', commonly known as alder buckthorn, glossy buckthorn, or breaking buckthorn, is a tall
deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
shrub in the family
Rhamnaceae
The Rhamnaceae are a large family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales.
The family contains about 55 genera and 950 species. The Rhamnaceae h ...
. Unlike other "buckthorns", alder buckthorn does not have thorns. It is native to
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 ...
, northernmost
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, and western
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 ...
, from
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
and
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
north to the
68th parallel in
Scandinavia
Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...
, east to central
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
and
Xinjiang
Xinjiang, SASM/GNC: ''Xinjang''; zh, c=, p=Xīnjiāng; formerly romanized as Sinkiang (, ), officially the Xinjiang Uygur Autonomous Region (XUAR), is an autonomous region of the People's Republic of China (PRC), located in the northwest ...
in western
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, and south to northern
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
,
Turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...
, and the
Alborz
The Alborz ( fa, البرز) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs nort ...
in
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
and
Caucasus Mountains
The Caucasus Mountains,
: pronounced
* hy, Կովկասյան լեռներ,
: pronounced
* az, Qafqaz dağları, pronounced
* rus, Кавка́зские го́ры, Kavkázskiye góry, kɐfˈkasːkʲɪje ˈɡorɨ
* tr, Kafkas Dağla ...
; in the northwest of its range (Ireland, Scotland), it is rare and scattered. It is also introduced and
naturalised
Naturalization (or naturalisation) is the legal act or process by which a non-citizen of a country may acquire citizenship or nationality of that country. It may be done automatically by a statute, i.e., without any effort on the part of the i ...
in eastern North America.
[Rushforth, K. (1999). ''Trees of Britain and Europe''. Collins .][Flora Europaea]
''Frangula alnus''
/ref>[Den virtuella floran]
(in Swedish, with detailed maps)[ Stace, Clive, et al. ''Interactive Flora of NW Europe'']
''Frangula alnus''
/ref>
Description
Alder buckthorn is a non-spiny deciduous shrub, growing to , occasionally to tall. It is usually multistemmed, but rarely forms a small tree with a trunk diameter of up to . The bark is dark blackish-brown, with bright lemon-yellow inner bark exposed if cut. The shoots are dark brown, the winter buds without bud scales, protected only by the densely hairy outer leaves.
The leaves are arranged alternately on petioles. They are ovate
Ovate may refer to:
*Ovate (egg-shaped) leaves, tepals, or other botanical parts
*Ovate, a type of prehistoric stone hand axe
*Ovates, one of three ranks of membership in the Welsh Gorsedd
*Vates
In modern English, the nouns vates () and ovat ...
, long by wide (rarely to by ). They have 6–10 pairs of prominently grooved and slightly downy veins and an entire margin
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...
.
The flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s are small, in diameter, star-shaped with five greenish-white acute triangular petal
Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...
s, hermaphroditic
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many taxonomic groups of animals (mostly invertebrates) do not have separ ...
, and insect-pollinated
Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, some ...
, flowering in May to June in clusters of two to ten in the leaf axil
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
s.
The fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
is a small black berry
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...
in diameter, ripening from green through red in late summer to dark purple or black in early autumn, containing two or three pale brown seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s. The seeds are primarily dispersed by frugivorous
A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...
birds, which readily eat the fruit.[Blamey, M. & Grey-Wilson, C. (1989). ''Flora of Britain and Northern Europe''. .]
Taxonomy and naming
Alder buckthorn was first formally described by Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in 1753 as ''Rhamnus frangula''. It was subsequently separated by Philip Miller
Philip Miller FRS (1691 – 18 December 1771) was an English botanist and gardener of Scottish descent. Miller was chief gardener at the Chelsea Physic Garden for nearly 50 years from 1722, and wrote the highly popular ''The Gardeners Dictio ...
in 1768 into the genus ''Frangula'' on the basis of its hermaphrodite flowers with a five-parted corolla (in ''Rhamnus'' the flowers are dioecious and four-parted); this restored the treatment of pre-Linnaean authors, notably Tournefort. Although much disputed historically, the separation of ''Frangula'' from ''Rhamnus'' is now widely accepted, being supported by recent genetic data though a few authorities still retain the genus within ''Rhamnus'' (e.g., the ''Flora of China'').
The genus name ''Frangula'', from Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
"to break", refers to the brittle wood. Both the common name alder buckthorn and specific epithet ''alnus'' refer to its association with alder
Alders are trees comprising the genus ''Alnus'' in 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 sp ...
s (''Alnus'') on damp sites. Unlike other "buckthorns", alder buckthorn does not have thorns.[Vedel, H., & Lange, J. (1960). ''Trees and Bushes in Wood and Hedgerow''. Methuen & Co Ltd.][Natural England]
Alder buckthorn
Other recorded names include glossy buckthorn and breaking buckthorn; historically, it was sometimes called "dogwood" through confusion of the leaves with those of dogwood
''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrub ...
''Cornus sanguinea''.
Ecology
Alder buckthorn grows in wet soils in open woods, scrub, hedgerows and bogs, thriving well in sunlight and moderate shade, but less vigorously in dense shade; it prefers acidic soils though will also grow on neutral soils.
''Frangula alnus'' is one of just two food plants (the other being ''Rhamnus cathartica
''Rhamnus cathartica'', the European buckthorn, common buckthorn, purging buckthorn, or just buckthorn, is a species of small tree in the flowering plant family Rhamnaceae. It is native to Europe, northwest Africa and western Asia, from the cen ...
'') used by the common brimstone
''Gonepteryx rhamni'' (known as the common brimstone) is a butterfly of the family Pieridae. It lives throughout the Palearctic realm, Palearctic zone and is commonly found across Europe, Asia, and North Africa. Across much of its range, it is ...
butterfly (''Gonepteryx rhamni''). The flowers are valuable for bee
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...
s, and the fruit an important food source for birds, particularly thrushes
The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists reclassified the former subfamily Saxicolinae, which includes the chats and European robins, as Old World flycat ...
.
Invasive species
''Frangula alnus'' was probably introduced to 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 ...
about 200 years ago, and in Canada about 100 years ago. It was planted for hedgerows, forestry plantings, and wildlife habitat, but has become an invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
, invading forests in the northeastern United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
and wetlands and moist forest in the Midwestern United States. It is predicted to continue to expand its North American range with time. Its invasiveness is assisted by its high adaptability and pollution tolerance. It is one of three species of buckthorn that occurs without cultivation in eastern Canada.
It invades forests and grows in the understory in spots with a lot of light. These areas, usually where a tree has fallen, normally allow locally native tree seedlings to grow and eventually fill in the gap in the canopy. But when ''Frangula alnus'' invades and grows in these locations, its dense canopy prevents light from reaching the ground and therefore prevents other seedlings from growing. It tends to grow more densely and with larger individuals in lower topographical areas with moist, fertile soils, and is very problematic for land managers. Uplands forests are not invaded as easily as lower lying ones. Hemlock-oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
stands, which tend to be older stands of trees, are much less suitable for ''Frangula alnus'' because the density of the tree canopy creates a more shady environment that is not as suitable for ''Frangula alnus''. Eastern white pine
''Pinus strobus'', commonly called the eastern white pine, northern white pine, white pine, Weymouth pine (British), and soft pine is a large pine native to eastern North America. It occurs from Newfoundland, Canada west through the Great Lakes ...
stands are easily invaded because they allow more light to reach the forest floor, and tree stands that are cut are very quickly invaded while undisturbed stands are rarely invaded.
Habitat fragmentation
Although considered an invasive species in North America, In other places, such as Northern Ireland, ''Frangula alnus'' has suffered greatly from habitat loss. This is due to the decline in its preferred habitats, which are boglands. It is currently only found on the southern side of Lough Neagh
Lough Neagh ( ) is a freshwater lake in Northern Ireland and is the largest lake in the island of Ireland, the United Kingdom and the British Isles. It has a surface area of and supplies 40% of Northern Ireland's water. Its main inflows come ...
, but it the past, it was also found on the northern side of the lake. Compared to other populations of ''Frangula alnus'', the population in Ireland also has lower genetic diversity.
Control
Small saplings can be hand-pulled, but control of larger examples is best achieved using herbicides. ''Frangula alnus'' and the related species ''Rhamnus cathartica
''Rhamnus cathartica'', the European buckthorn, common buckthorn, purging buckthorn, or just buckthorn, is a species of small tree in the flowering plant family Rhamnaceae. It is native to Europe, northwest Africa and western Asia, from the cen ...
'' have been banned from sale, transport, or import to Minnesota
Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
and Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
. It is considered invasive, but not banned, in Connecticut
Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its cap ...
.
Uses
Decorative
Alder buckthorn has limited decorative qualities without conspicuous flowers or bold foliage, and is mainly grown for its conservation value, particularly to attract Brimstone butterflies. A variegated
Variegation is the appearance of differently coloured zones in the leaves and sometimes the stems and fruit of plants. Species with variegated individuals are sometimes found in the understory of tropical rainforests, and this habitat is the s ...
cultivar ''Frangula alnus'' 'Variegata' and a cultivar with very slender leaves 'Asplenifolia' are sometimes grown in gardens as ornamental shrubs. The cultivar 'Tallhedge' has been selected for hedging.
Medicinal
Galen
Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of ...
, a Greek physician of the 2nd century A.D., knew of alder buckthorn, although he did not distinguish clearly in his writings between it and other closely related species. All of these plants though, were credited with the power to protect against witchcraft, demons, poisons, and headaches.
The bark (and to a lesser extent the fruit) has been used as a laxative
Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation.
Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
, due to its 3–7% anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxo ...
content. Bark for medicinal use is dried and stored for a year before use, as fresh bark is violently purgative; even dried bark can be dangerous if taken in excess.
Other uses
Alder buckthorn charcoal is prized in the manufacture of gunpowder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). ...
, being regarded as the best wood for the purpose. It is particularly highly valued for time fuses because of its very even burn rate. The wood was formerly used for shoe last
A shoe is an item of footwear intended to protect and comfort the human foot. They are often worn with a sock. Shoes are also used as an item of decoration and fashion. The design of shoes has varied enormously through time and from culture ...
s, nails, and veneer. The bark yields a yellow dye, and the unripe berries furnish a green dye.
References
Further reading
*
External links
''Frangula alnus''
- information, genetic conservation units and related resources. European Forest Genetic Resources Programme
European Forest Genetic Resources Programme (EUFORGEN) is an international network that supports the conservation and sustainable use of forest genetic resources in Europe. The programme’s tasks include to coordinate and promote ''in situ
' ...
(EUFORGEN)
''Frangula alnus''
''-'' Alder Buckthorn; info, images and video a
Woodland Trust
{{Authority control
alnus
Alders are trees comprising the genus ''Alnus'' in 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 spec ...
Flora of Europe
Flora of North Africa
Flora of Western Asia
Flora of Central Asia
Flora of Siberia
Flora of Russia
Flora of Xinjiang
Plants described in 1753
Taxa named by Carl Linnaeus
Taxa named by Philip Miller