Beech (genus Fagus) is a genus of deciduous trees in the family Fagaceae, native to subtropical (accessory forest element) and temperate (as dominant element of mesophytic forests) Eurasia and North America. There are 14 accepted species in two distinct subgenera, Englerianae and Fagus. The subgenus Englerianae is found only in East Asia, distinctive for its low branches, often made up of several major trunks with yellowish bark. The better known species of subgenus Fagus are native to Europe, western and eastern Asia and eastern North America.
The European beech Fagus sylvatica is the most commonly cultivated species, with several ornamental varieties, and forest trees yielding a timber used for furniture, flooring and construction, plywood, and household items. The timber can be used to build homes. Beechwood makes excellent firewood. Slats of washed beech wood are spread around the bottom of fermentation tanks for some beers. Beech logs are burned to dry the malt used in some German smoked beers. Beech is also used to smoke Westphalian ham, andouille sausage, and some cheeses.
Description
Beeches are monoecious, bearing both male and female flowers on the same plant. The small flowers are unisexual, the female flowers borne in pairs, the male flowers wind-pollinating catkins. The fruit is a three-angled nut, with two in a spiny dehiscent cupule. The bark is smooth. The leaves have a central vein with side-veins parallel to each other and ending in a tooth on the thin leaf-blade. The tree is deciduous, dropping its leaves in autumn.
Evolution
Evolutionary history
Numerous species have been named globally from the fossil record spanning from the Cretaceous to the Pleistocene. Some fossil species formerly placed in Fagus have been moved to other genera, namely Alnus, Castanea, Fagopsis, Fagoxylon, Fagus-pollenites, Juglans, Nothofagaphyllites, Nothofagus, and Trigonobalanus.
Fagus is the first diverging lineage in the evolution of the Fagaceae family, which includes oaks and chestnuts. The oldest fossils that can be assigned to the beech lineage are 81–82 million years old pollen from the Late Cretaceous of Wyoming, United States.
The first representatives of the modern-day genus were likely already present in the Paleocene of Arctic North America (western Greenland) and quickly radiated across the high latitudes of the Northern Hemisphere, with a first diversity peak in the Miocene of northeastern Asia. The contemporary species are the product of past, repeated reticulate evolutionary processes (outbreeding, introgression, hybridization). As far as studied, heterozygosity and intragenomic variation are common in beech species, and their chloroplast genomes are nonspecific with the exception of the Western Eurasian and North American species.
Phylogeny
A cladogram of 11 extant beech species is shown below. The subgenera Engleriana and Fagus diverged from each other in the Early Oligocene era, 32.1 to 33.4 million years ago.
Taxonomy
The most recent classification system of the genus recognizes 14 species in two distinct subgenera, subgenus Englerianae and Fagus. Beech species can be diagnosed by phenotypical and/or genotypical traits. Species of subgenus Engleriana are found only in East Asia, and are notably distinct from species of subgenus Fagus in that these beeches are low-branching trees, often made up of several major trunks with yellowish bark and a substantially different nucleome (nuclear DNA), especially in noncoding, highly variable gene regions such as the spacers of the nuclear-encoded ribosomal RNA genes (ribosomal DNA). Further differentiating characteristics include the whitish bloom on the underside of the leaves, the visible tertiary leaf veins, and a long, smooth cupule-peduncle. Originally proposed but not formalized by botanist Chung-Fu Shen in 1992, this group comprised two Japanese species, F. japonica and F. okamotoi, and one Chinese species, F. engleriana. While the status of F. okamotoi remains uncertain, the most recent systematic treatment based on morphological and genetic data confirmed a third species, F. multinervis, endemic to Ulleungdo, a South Korean island in the Sea of Japan. The beeches of Ulleungdo have been traditionally treated as a subspecies of F. engleriana, to which they are phenotypically identical, or as a variety of F. japonica. The differ from their siblings by their unique nuclear and plastid genotypes.
The better known subgenus Fagus beeches are high-branching with tall, stout trunks and smooth silver-grey bark. This group includes five extant species in continental and insular East Asia (F. crenata, F. longipetiolata, F. lucida, and the cryptic sister species F. hayatae and F. pashanica), two pseudo-cryptic species in eastern North America (F. grandifolia, F. mexicana), and a species complex of at least four species (F. caspica, F. hohenackeriana, F. orientalis, F. sylvatica) in Western Eurasia. Their genetics are highly complex and include both species-unique alleles as well as alleles and ribosomal DNA spacers that are shared between two or more species. The western Eurasian species are characterised by morphological and genetical gradients.
Species
Species treated in Denk et al. (2024) and listed in Plants of the World Online (POWO): Image Name SubgenusStatus, systematic affinity Distribution Accepted in POWO, Sept. 2025Fagus caspica – Caspian beechFagusNew species described in 2024; first-diverging lineage within the Western Eurasian groupTalysch and Elburz Mountains, southeastern Azerbaijan and northern IranNo mention Fagus chienii FagusPossibly conspecific with F. lucida Probably extinct, described from a single location in China (Sichuan). Individuals collected there were morphologically and genetically indistinguishable from F. pashanica.YesFagus crenata – Siebold's beech or Japanese beechFagusWidespread species; complex history connecting it to both the Western Eurasian group and the other East Asian species of subgenus FagusJapan; in the mountains of Kyushu, Shikoku and Honshu, down to sea-level in southern Hokkaido.YesFagus engleriana – Chinese beechEnglerianaeWidespread species; continental sister species of F. japonicaChina; south of the Yellow RiverYesFagus grandifolia – American beechFagusWidespread species; sister species of F. mexicanaEastern North America; from E. Texas and N. Florida, United States, to the St. Lawrence River, Canada at low to mid altitudesYesFagus hayatae FagusNarrow endemic species; forming a cryptic sister species pair with F. pashanicaTaiwan; restricted to the mountains of northern TaiwanYesFagus hohenackeriana – Caucasian or Hohenacker's beechFagusDominant tree species of the Pontic and Caucasus Mountains; intermediate between F. caspica and F. orientalis. Its genetic heterogeneity may be indicative for ongoing speciation processes.Northeastern Anatolia (Pontic Mountains, Kaçkar Mountains) and Caucasus region (Lesser and Greater Caucasus, Georgia, Armenia, Ciscaucasia; down to sea-level in southwestern Georgia)YesFagus japonica File:Fagus mexicana, Zacualtipán de Ángeles, Hidalgo, Mexico 5737290.jpgEnglerianaeWidespread species; insular sister species of F. englerianaJapan; Kyushu, Shikoku and Honshu from sea-level up to c. 1500 m a.s.l.YesFagus longipetiolata FagusSym- to parapatric with F. lucida and F. pashanica, and sharing alleles with both species in addition to alleles indicating a sister relationship with the Japanese F. crenata.China, south of the Yellow River, into N. Vietnam; in montane areas up to 2400 m a.s.l.Replaced by F. sinensisFagus lucida FagusRare species; closest relatives are F. crenata and F. longipetiolataChina; south of the Yellow River in montane areas between 800 and 2000 m a.s.l.YesFagus mexicana FagusNarrow endemic sister species of F. grandifolia. F. mexicana differs from F. grandifolia by its slender leaves and less-evolved but more polymorphic set of alleles (higher level of heterozygosity)Hidalgo, Mexico; at 1400–2000 m a.s.l. as an element of the subtropical montane mesophilic forest (bosque mesófilo de montaña) superimposing the tropical lowland rainforests.Yes Fagus multinervis EnglerianaeNarrow endemic species, first diverging lineage within subgenus Englerianae South Korea (Ulleungdo)Yes Fagus orientalis – Oriental beech (in a narrow sense)FagusSister species of F. sylvaticaSoutheastern Europe (SE Bulgaria, NE Greece, East Thrace (European Turkey) and adjacent northwestern Asia (NW and N Anatolia) Yes Fagus pashanica FagusContinental sister species of F. hayatae, with a set of alleles that puts it closer to F. longipetiolata and F. crenata than its insular sister. China (Hubei, Hunan, Shaanxi, Sichuan, Zhejiang), at 1300–2300 m a.s.l.(eFlora of China, as F. hayatae) Yes Fagus sinensis FagusInvalid; the original material included material from two much different species: F. engleriana and F. longipetiolata China (Hubei), VietnamYes, erroneously used as older synonym of F. longipetiolata Fagus sylvatica – European beechFagusSister species of and closely related to F. orientalis EuropeYes
Natural and potential hybrids
Name Parentage Status Distribution Fagus (×) moesiaca F. sylvatica × F. orientalisNo evidence so far for hybrid origin. All individuals addressed as F. moesiaca included in genetic studies fell within the variation of F. sylvatica. They may represent a lowland ecotype of F. sylvatica.Southeastern BalkansFagus × taurica – Crimean beech F. sylvatica × F. orientalis s.l.Hybrid status not yet tested by genetic data; according to isoenzyme profiles a less-evolved, relict population of F. sylvatica or intermediate between F. sylvatica and the species complex historically addressed as Oriental beech (F. orientalis in a broad sense)Crimean peninsula
Etymology
The name of the tree in Latin, fagus (whence the generic epithet), is cognate with English "beech" and of Indo-European origin. It played a role in early debates on the geographical origins of the Indo-European people, the beech argument. Greek φηγός (figós) is from the same root, but the word was transferred to the oak tree (e.g. Iliad 16.767) as a result of the absence of beech trees in southern Greece.
The common name of "beech" is from the Anglo-Saxon boc, bece or beoce, the German buche, the Swedish box - all meaning "book" as well as beech and derived from the Sanskrit boko or letter and bokos or writings. This connection to "beech" seems to have derived from the fact that the old Runic tablets were of beech wood.
Ecology
Habitat and distribution
Beech requires a deep soil with good drainage and a neutral or slightly acidic soil, pH 6 to 7.5. It is vulnerable to drought as its root system is relatively shallow. It does not live in waterlogged areas, but it can grow in windy places, shade from other trees, and cold. In northern Europe it is a lowland species, while further south it is montane, growing at an altitude of up to .
The English Lowlands beech forests is an ecoregion of high-canopy forest dominated by European beech in southeastern England, surviving as remnants such as the New Forest. The species arrived in Britain after the last glaciation, and may have been restricted to basic soils in the south of England. It could have been introduced by Neolithic tribes who planted the trees for their edible nuts. In southeast Wales, the Cwm Clydach National Nature Reserve holds beech woodlands on the western edge of their natural range in a steep limestone gorge. The primeval beech forests of the Carpathians have been dominated since the last ice age by the beech. In North America, beech can form Beech-maple forest, seen by some ecologists as a climax community, by partnering with the sugar maple.
Pests and diseases
The beech blight aphid, Grylloprociphilus imbricator, is a common pest of American beech trees.