![Catkins Corylus avellana-Mont Bart-5124~2015 12 26](https://upload.wikimedia.org/wikipedia/commons/4/4c/Catkins_Corylus_avellana-Mont_Bart-5124~2015_12_26.JPG)
The hazel (''Corylus'') is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
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 ...
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s and large
shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
s native to the
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
Northern Hemisphere. The genus is usually placed in the
birch
A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...
family
Betulaceae
Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of the t ...
,
[Germplasmgobills Information Network]
''Corylus''
[Rushforth, K. (1999). ''Trees of Britain and Europe''. Collins .][Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan .] though some botanists split the hazels (with the
hornbeam
Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere.
Origin of names
The common English name ''hornbeam' ...
s and allied genera) into a separate family Corylaceae. The fruit of the hazel is the
hazelnut
The hazelnut is the fruit of the hazel tree and therefore includes any of the nuts deriving from species of the genus ''Corylus'', especially the nuts of the species ''Corylus avellana''. They are also known as cobnuts or filberts according t ...
.
Hazels have simple, rounded
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 ...
with double-serrate margins. 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 produced very early in spring before the leaves, and are
monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy.
Monoecy is conne ...
, with single-sex
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. The male catkins are pale yellow and long, and the female ones are very small and largely concealed in the buds, with only the bright-red, 1-to-3 mm-long
styles visible. The fruits are
nuts long and 1–2 cm diameter, surrounded by an involucre (husk) which partly to fully encloses the nut.
[
The shape and structure of the ]involucre
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...
, and also the growth habit (whether a tree or a suckering shrub), are important in the identification of the different species of hazel.[
The pollen of hazel species, which are often the cause for allergies in late winter or early spring, can be identified under magnification (600×) by their characteristic granular ]exine
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
s bearing three conspicuous pores.
Species
''Corylus'' has 14–18 species. The circumscription of species in eastern Asia
East Asia is the eastern region of Asia, which is defined in both Geography, geographical and culture, ethno-cultural terms. The modern State (polity), states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. ...
is disputed, with ''WCSP'' and the ''Flora of China'' differing in which taxa are accepted; within this region, only those taxa accepted by both sources are listed below.[WCSP]
''Corylus''
/ref>[Flora of China]
''Corylus''
/ref>[Flora of North America]
''Corylus''
/ref> The species are grouped as follows:
* Nut surrounded by a soft, leafy involucre
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...
, multiple-stemmed, suckering shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
s to 12 m tall
** Involucre short, about the same length as the nut
*** ''Corylus americana
''Corylus americana'', the American hazelnut or American hazel, is a species of deciduous shrub in the genus ''Corylus'', native to the eastern and central United States and extreme southern parts of eastern and central Canada.
Description
The A ...
'' – American hazel, eastern 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 ...
*** ''Corylus avellana
''Corylus avellana'', the common hazel, is a species of flowering plant in the birch family Betulaceae. It is native to Europe and western Asia. It is an important component of the hedgerows that were the traditional field boundaries in lowland En ...
'' – Common hazel, 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 western Asia
Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Ana ...
*** ''Corylus heterophylla
''Corylus heterophylla'', the Asian hazel, is a species of hazel native to eastern Asia in northern and central China, Korea, Japan, and southeastern Siberia.Flora of China''Corylus heterophylla''/ref>
It is a deciduous shrub or small tree gr ...
'' – Asian hazel, 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 ...
*** ''Corylus yunnanensis
''Corylus yunnanensis'', the Yunnan hazel, is a species of hazel
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,G ...
'' – Yunnan hazel, central and southern 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 ...
** Involucre long, twice the length of the nut or more, forming a 'beak'
*** ''Corylus colchica
''Corylus colchica'' also known as ''Corylus iberica'' is a species of hazelnut endemic to Armenia and Georgia in the Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, ...
'' – Colchican filbert, 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 ...
*** ''Corylus cornuta
''Corylus cornuta'', the beaked hazelnut (or just ''beaked hazel''), is a deciduous shrubby hazel with two subspecies found throughout most of North America.
Description
The beaked hazelnut can reach tall with stems thick with smooth gray ...
'' – Beaked hazel, North America
*** ''Corylus maxima
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
'' – Filbert, southeastern
The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...
Europe and southwest Asia
Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Anat ...
*** ''Corylus sieboldiana
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
'' – Asian beaked hazel, northeastern 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 Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
(syn. ''C. mandshurica'')
* Nut surrounded by a stiff, spiny involucre, single-stemmed tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s to 20–35 m tall
** Involucre moderately spiny and also with glandular hairs
*** ''Corylus chinensis
''Corylus chinensis'', common names Chinese filbert and Chinese hazel, is a deciduous tree native to western China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous countr ...
'' – Chinese hazel, western China
*** ''Corylus colurna
''Corylus colurna'', the Turkish hazel or Turkish filbert, is a deciduous tree native to southeast Europe and southwest Asia, from the Balkans through northern Turkey to northern Iran. It is also found growing wild in the forests of Western Himal ...
'' – Turkish hazel, southeastern Europe and Asia Minor
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
*** '' Corylus fargesii'' – Farges' hazel, western China
*** ''Corylus jacquemontii
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
'' – Jacquemont's hazel, Himalaya
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...
*** ''Corylus wangii
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
'' – Wang's hazel, southwest 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 ...
** Involucre densely spiny, resembling a chestnut burr
*** ''Corylus ferox
''Corylus ferox'', the Himalayan hazelnut or Tibetan hazelnut, is a species of hazel native to the Himalayas of eastern Asia. '' – Himalayan hazel, Himalaya, Tibet
Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa people, ...
and southwest China (syn. ''C. tibetica'').
Several hybrids exist, and can occur between species in different sections of the genus, e.g. ''Corylus × colurnoides
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
'' (''C. avellana'' × ''C. colurna''). The oldest confirmed hazel species is ''Corylus johnsonii
''Corylus johnsonii'' is an extinct species of hazel known from fossil fruits found in the Klondike Mountain Formation deposits of northern Washington state, dated to the early Eocene Ypresian stage (). Based on described features, ''C. johnsonii ...
'' found as fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s in the Ypresian
In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...
-age rocks of Ferry County, Washington
Ferry County is a county located on the northern border of the U.S. state of Washington. As of the 2020 census, the population was 7,178, making it the fourth-least populous county in Washington. The county seat and largest city is Republic. Th ...
.
Ecology
At least 21 species of fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...
have a mutualistic relationship with hazel. ''Lactarius pyrogalus
''Lactarius pyrogalus'', commonly known as the fire-milk lactarius, is a species of inedible mushroom in genus ''Lactarius (fungus), Lactarius''. It is greyish and differentiated from other grey ''Lactarius'' by its widely spaced, yellow gill ...
'' grows almost exclusively on hazel, and hazel is one of two kinds of host for the rare ''Hypocreopsis rhododendri
''Hypocreopsis rhododendri'' is an ascomycete fungus. It is commonly known as hazel gloves due to the resemblance of its orange-brown, radiating lobes to rubber gloves, and because it is found on hazel (''Corylus avellana'') stems.
Distribution ...
''. Several rare species of Graphidion lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.[moth
Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...]
are specialised to feed on hazel including ''Parornix devoniella
''Parornix devoniella'' is a moth of the family Gracillariidae. It is known from all of Europe (except the Iberian Peninsula, the Balkan Peninsula and the Mediterranean Sea, Mediterranean islands).
The wingspan is 9–10 mm. The head is w ...
''. Animals which eat hazelnuts include red deer
The red deer (''Cervus elaphus'') is one of the largest deer species. A male red deer is called a stag or hart, and a female is called a hind. The red deer inhabits most of Europe, the Caucasus Mountains region, Anatolia, Iran, and parts of wes ...
, dormouse
A dormouse is a rodent of the family Gliridae (this family is also variously called Myoxidae or Muscardinidae by different taxonomists). Dormice are nocturnal animals found in Africa, Asia, and Europe. They are named for their long, dormant hibe ...
and red squirrel
The red squirrel (''Sciurus vulgaris'') is a species of tree squirrel in the genus ''Sciurus'' common throughout Europe and Asia. The red squirrel is an arboreal, primarily herbivorous rodent.
In Great Britain, Ireland, and in Italy numbers ...
.
Uses
The nuts of all hazels are edible. The common hazel
''Corylus avellana'', the common hazel, is a species of flowering plant in the birch family Betulaceae. It is native to Europe and western Asia. It is an important component of the hedgerows that were the traditional field boundaries in lowland En ...
is the species most extensively grown for its nuts, followed in importance by the filbert. Nuts are also harvested from the other species, but apart from the filbert, none is of significant commercial importance.[
A number of ]cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...
s of the common hazel and filbert are grown as ornamental plant
Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...
s in garden
A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate both ...
s, including forms with contorted stems (''C. avellana'' 'Contorta', popularly known as "Corkscrew hazel" or "Harry Lauder
Sir Henry Lauder (; 4 August 1870 – 26 February 1950)Russell, Dave"Lauder, Sir Henry (1870–1950)" ''Oxford Dictionary of National Biography'', Oxford University Press, 2004, online edition, January 2011, accessed 27 April 2014 was a S ...
's walking stick" from its gnarled appearance); with weeping branches (''C. avellana'' 'Pendula'); and with purple leaves (''C. maxima'' 'Purpurea').
Hazel is a traditional material used for making wattle
Wattle or wattles may refer to:
Plants
*''Acacia sensu lato'', polyphyletic genus of plants commonly known as wattle, especially in Australia and South Africa
**''Acacia'', large genus of shrubs and trees, native to Australasia
**Black wattle, c ...
, withy
A withy or withe (also willow and osier) is a strong flexible willow stem, typically used in thatching, basketmaking, gardening and for constructing woven wattle hurdles. fencing, baskets, and the frames of coracle
A coracle is a small, rounded, lightweight boat of the sort traditionally used in Wales, and also in parts of the West Country and in Ireland, particularly the River Boyne, and in Scotland, particularly the River Spey. The word is also used of s ...
boats. The tree can be coppiced
Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeated ...
, and regenerating shoots allow for harvests every few years.
Hazels are used as food plants by the larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e of various 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 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 ...
.
Culture
The Celts believed hazelnuts gave one wisdom and inspiration. There are numerous variations on an ancient tale that nine hazel trees grew around a sacred pool, dropping into the water nuts that were eaten by salmon
Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...
(a fish sacred to Druid
A druid was a member of the high-ranking class in ancient Celtic cultures. Druids were religious leaders as well as legal authorities, adjudicators, lorekeepers, medical professionals and political advisors. Druids left no written accounts. Whi ...
s), which absorbed the wisdom. A Druid teacher, in his bid to become omniscient
Omniscience () is the capacity to know everything. In Hinduism, Sikhism and the Abrahamic religions, this is an attribute of God. In Jainism, omniscience is an attribute that any individual can eventually attain. In Buddhism, there are diffe ...
, caught one of these special salmon and asked a student to cook the fish, but not to eat it. While he was cooking it, a blister formed and the pupil used his thumb to burst it, which he naturally sucked to cool, thereby absorbing the fish's wisdom. This boy was called Fionn Mac Cumhail
Fionn mac Cumhaill ( ; Old and mga, Find or ''mac Cumail'' or ''mac Umaill''), often anglicized Finn McCool or MacCool, is a hero in Irish mythology, as well as in later Scottish and Manx folklore. He is leader of the ''Fianna'' bands of ...
(Fin McCool) and went on to become one of the most heroic leaders in Gaelic mythology
Celtic mythology is the body of myths belonging to the Celts, Celtic peoples.Cunliffe, Barry, (1997) ''The Ancient Celts''. Oxford, Oxford University Press , pp. 183 (religion), 202, 204–8. Like other Iron Age Europe, Iron Age Europeans, Ce ...
.[Floriz]
Mythology and Folklore of the Hazel Tree
"The Hazel Branch" from ''Grimms' Fairy Tales
''Grimms' Fairy Tales'', originally known as the ''Children's and Household Tales'' (german: Kinder- und Hausmärchen, lead=yes, ), is a German collection of fairy tales by the Brothers Grimm, Grimm brothers or "Brothers Grimm", Jacob Grimm, Ja ...
'' claims that hazel branches offer the greatest protection from snakes and other things that creep on the earth. In the Grimm tale "Cinderella", a hazel branch is planted by the protagonist at her mother's grave and grows into a tree that is the site where the girl's wishes are granted by birds.[Pitt.edu https://www.pitt.edu/~dash/grimm021.html June 1, 2011]
Gallery
File:Corylus fargesii, Arnold Arboretum - IMG 6165.JPG, Form (Farges' hazel)
File:Hazel Catkins.jpg, Male catkins (common hazel)
File:Hazel Flower Female.jpg, Female flower (common hazel)
File:TurkHazel.jpg, Leaves and nuts with spiny husks (Turkish hazel)
File:Hazelnuts.jpg, Hazelnuts
The hazelnut is the fruit of the hazel tree and therefore includes any of the nuts deriving from species of the genus ''Corylus'', especially the nuts of the species ''Corylus avellana''. They are also known as cobnuts or filberts according t ...
File:Hazelnut (male flower), overlay of 7 channel autofluorescence microscopy (30458886372).jpg, Closeup of a male hazelnut flower using autofluorescence
Autofluorescence is the natural emission of light by biological structures such as mitochondria and lysosomes when they have absorbed light, and is used to distinguish the light originating from artificially added fluorescent markers (fluorophores) ...
microscopy.
References
External links
*
{{Authority control
Edible nuts and seeds
Taxa named by Carl Linnaeus