Beech

Beech is a genus of deciduous trees in the family Fagaceae, native to subtropical and temperate 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 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. 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, especially in noncoding, highly variable gene regions such as the spacers of the nuclear-encoded ribosomal RNA genes. 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, two pseudo-cryptic species in eastern North America, and a species complex of at least four species 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. and listed in Plants of the World Online :

Image	Name	Subgenus	Status, systematic affinity	Distribution	Accepted in POWO, Sept. 2025
	Fagus caspica – Caspian beech	Fagus	New species described in 2024; first-diverging lineage within the Western Eurasian group	Talysch and Elburz Mountains, southeastern Azerbaijan and northern Iran	No mention
	Fagus chienii W.C.Cheng	Fagus	Possibly conspecific with F. lucida	Probably extinct, described from a single location in China. Individuals collected there were morphologically and genetically indistinguishable from F. pashanica.	Yes
	Fagus crenata Blume – Siebold's beech or Japanese beech	Fagus	Widespread species; complex history connecting it to both the Western Eurasian group and the other East Asian species of subgenus Fagus	Japan; in the mountains of Kyushu, Shikoku and Honshu, down to sea-level in southern Hokkaido.	Yes
	Fagus engleriana Seemen ex Diels – Chinese beech	Englerianae	Widespread species; continental sister species of F. japonica	China; south of the Yellow River	Yes
	Fagus grandifolia Ehrh. – American beech	Fagus	Widespread species; sister species of F. mexicana	Eastern North America; from E. Texas and N. Florida, United States, to the St. Lawrence River, Canada at low to mid altitudes	Yes
	Fagus hayatae Palib. ex Hayata	Fagus	Narrow endemic species; forming a cryptic sister species pair with F. pashanica	Taiwan; restricted to the mountains of northern Taiwan	Yes
	Fagus hohenackeriana – Caucasian or Hohenacker's beech	Fagus	Dominant 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 and Caucasus region	Yes
	Fagus japonica Maxim.File:Fagus mexicana, Zacualtipán de Ángeles, Hidalgo, Mexico 5737290.jpg	Englerianae	Widespread species; insular sister species of F. engleriana	Japan; Kyushu, Shikoku and Honshu from sea-level up to c. 1500 m a.s.l.	Yes
	Fagus longipetiolata	Fagus	Sym- 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. sinensis
	Fagus lucida Rehder & E.H.Wilson	Fagus	Rare species; closest relatives are F. crenata and F. longipetiolata	China; south of the Yellow River in montane areas between 800 and 2000 m a.s.l.	Yes
	Fagus mexicana	Fagus	Narrow 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	Hidalgo, Mexico; at 1400–2000 m a.s.l. as an element of the subtropical montane mesophilic forest superimposing the tropical lowland rainforests.	Yes
	Fagus multinervis Nakai	Englerianae	Narrow endemic species, first diverging lineage within subgenus Englerianae	South Korea	Yes
	Fagus orientalis Lipsky – Oriental beech	Fagus	Sister species of F. sylvatica	Southeastern Europe and adjacent northwestern Asia	Yes
	Fagus pashanica C.C.Yang	Fagus	Continental 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, at 1300–2300 m a.s.l.	Yes
	Fagus sinensis Oliv.	Fagus	Invalid; the original material included material from two much different species: F. engleriana and F. longipetiolata	China, Vietnam	Yes, erroneously used as older synonym of F. longipetiolata
	Fagus sylvatica L. – European beech	Fagus	Sister species of and closely related to F. orientalis''	Europe	Yes