TheFagaceae (/fəˈɡeɪsi.iː,-ˌaɪ/; from Latinfagus'beech tree') are a family offlowering plants that includesbeeches,chestnuts andoaks, and comprises eight genera with around 1,000 or more species.[2][3][4] Fagaceae in temperate regions are mostlydeciduous, whereas in the tropics, many species occur asevergreen trees and shrubs. They are characterized by alternate simpleleaves with pinnate venation, unisexualflowers in the form ofcatkins, and fruit in the form of cup-like (cupule) nuts. Their leaves are often lobed, and bothpetioles andstipules are generally present. Their fruits lackendosperm and lie in a scaly or spiny husk that may or may not enclose the entire nut, which may consist of one to seven seeds. In theoaks, genusQuercus, the fruit is a non-valved nut (usually containing one seed) called an acorn. The husk of the acorn in most oaks only forms a cup in which the nut sits. Other members of the family have fully enclosed nuts. Fagaceae is one of the most ecologically important woody plant families in the Northern Hemisphere, as oaks form the backbone oftemperate forest in North America, Europe, and Asia, and are one of the most significant sources of wildlife food.
Several members of the Fagaceae have important economic uses. Many species ofoak,chestnut, andbeech (generaQuercus,Castanea, andFagus, respectively) are commonly used as timber for floors, furniture, cabinets, and wine barrels. Cork for stopping wine bottles and a myriad other uses is made from the bark of cork oak,Quercus suber.Chestnuts are the fruits from species of the genusCastanea. Numerous species from several genera are prominent ornamentals. Wood chips from the genusFagus are often used in flavoring beers. Nuts of some species in the Asian tropical generaCastanopsis andLithocarpus are edible and often used as ornamentals.
The Fagaceae are often divided into five or six subfamilies and are generally accepted to include 8 (to 10) genera (listed below).Monophyly of the Fagaceae is strongly supported by bothmorphological (especially fruit morphology) andmolecular data.[5]
The Southern Hemisphere genusNothofagus, commonly thesouthern beeches, was historically placed in the Fagaceae sister to the genusFagus,[6] but recent molecular evidence suggests otherwise. WhileNothofagus shares a number of common characteristics with the Fagaceae, such as cupule fruit structure, it differs significantly in a number of ways, including distinct stipule and pollen morphology, as well as having a different number ofchromosomes.[7] The currently accepted view by systematic botanists is to placeNothofagus in its own family,Nothofagaceae.[5]
FagusL.—beeches; about 10 to 13 species, north temperate east Asia, southwest Asia, Europe, eastern North America
The genusNothofagus (southern beeches: from the Southern Hemisphere), formerly included in the Fagaceae, is now treated in the separate monotypic familyNothofagaceae.[8]
TrigonobalanusForman 1962—three species, tropical southeast Asia, Northern South America (Colombia) (three species ofColombobalanus andFormanodendron are included)
TheQuercus subgenusCyclobalanopsis is treated as a distinct genus by theFlora of China, but as a section or subgenus by most taxonomists.
^abJudd, Walter S.; Campbell, Christopher S.; Kellogg, Elizabeth A.; Stevens, Peter F.; Donoghue, Michael J. (2008).Plant Systematics: A Phylogenetic Approach (3rd ed.). Sinauer.ISBN978-0-87893-407-2.
^Manos PS, Stanford AM (2001). "The historical biogeography of Fagaceae: Tracking the tertiary history of temperate and subtropical forests of the Northern Hemisphere".International Journal of Plant Sciences.162 (Suppl. 6):S77 –S93.doi:10.1086/323280.S2CID84936653.
^Xiang X-G, Wang W, Li R-Q, Lin L, Liu Y, Zhou Z-K, Li Z-Y, Chen Z-D (2014). "Large-scale phylogenetic analyses reveal fagalean diversification promoted by the interplay of diaspores and environments in the Paleogene".Perspectives in Plant Ecology, Evolution and Systematics.16 (3):101–110.Bibcode:2014PPEES..16..101X.doi:10.1016/j.ppees.2014.03.001.
