Fagaceae

Taxobox
name = Beech family

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image_width = 250px
image_caption = Holm Oak ("Quercus ilex" subsp. "rotundifolia")
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Fagales
familia = Fagaceae
familia_authority = Dumortier
subdivision_ranks = Genera
subdivision = "Castanea" - Chestnuts "Castanopsis" "Chrysolepis" - Golden chinkapin "Colombobalanus" "Fagus" - Beeches "Formanodendron" "Lithocarpus" - Stone oaks "Quercus" - Oaks "Trigonobalanus"

The family Fagaceae, or beech family, comprises about 900 species of both evergreen and deciduous trees and shrubs, which are characterized by alternate simple leaves with pinnate venation, unisexual flowers in the form of catkins, and fruit in the form of cup-like (cupule) nuts. Fagaceous leaves are often lobed and both petioles and stipules are generally present. Fruits lack endosperm 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. The best-known group of this family is the oaks, genus "Quercus", the fruit of which 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.

Several members of the Fagaceae have important economic uses. Many species of oak, chestnut, and beech (genera "Quercus", "Castanea", and "Fagus" respectively) are commonly used as timber for floors, furniture, cabinets, and wine barrels. Cork for stopping wine bottles and a myriad of other uses is made from the bark of cork oak, "Quercus suber." Chestnuts, a tasty treat enjoyed by many in the winter, are the fruits from species of the genus "Castanea." Numerous species from several genera are prominent ornamentals, and wood chips from the genus "Fagus" are often used in flavoring beers.

Classification

The Fagaceae are often divided into three or four subfamilies and are generally accepted to include nine or ten genera (listed below). Monophyly of the Fagaceae is strongly supported by both morphological (especially fruit morphology) and molecular data. [Judd, Walter S., Christopher S. Campbell, Elizabeth A. Kellogg, Peter F. Stevens, Michael J. Donoghue. "Plant Systematics: A Phylogenetic Approach Third Edition". Sinauer Associates, inc. Sunderland, MA 2008.]

The Southern Hemisphere genus "Nothofagus," commonly the southern beeches, was historically placed in the Fagaceae sister to the genus "Fagus" [Cronquist, Arthur. "An Integrated System of Classification of Flowering Plants". Columbia University Press: New York, NY 1981.] , but recent molecular evidence suggests otherwise. While "Nothofagus" 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 of chromosomes. [Takhtajan, Armen. "Diversity and Classification of Flowering Plants". Columbia University Press, New York 1997.] The currently accepted view by systematic botanists is to place "Nothofagus" in its own family, Nothofagaceae. [Judd, Walter S., Christopher S. Campbell, Elizabeth A. Kellogg, Peter F. Stevens, Michael J. Donoghue. "Plant Systematics: A Phylogenetic Approach Third Edition". Sinauer Associates, inc. Sunderland, MA 2008.]

Genera

*"Castanea" - Chestnuts; eight species, north temperate east Asia, southwest Asia, southeast Europe, eastern North America
*"Castanopsis" - chinquapins or chinkapins about 125-130 species, southeast Asia
*"Chrysolepis" - Golden chinkapins; two species, western USA
*"Colombobalanus" - one species "C. excelsa", northern South America, often included in "Trigonobalanus"
*"Fagus" - Beeches; 10 species, north temperate east Asia, southwest Asia, Europe, eastern North America
*"Formanodendron" - one species "F. doichangensis", southeast Asia, often included in "Trigonobalanus"
*"Lithocarpus" - Tanoaks or Stone oaks; about 330-340 species, all but one in warm temperate to tropical Asia, the one ("L. densiflorus") in California and southwest Oregon
*"Quercus" - Oaks; about 500 species, widespread Northern Hemisphere, crossing the equator in Indonesia
*"Trigonobalanus" - one species "T. verticillata", tropical southeast Asia (three species if "Colombobalanus" and "Formanodendron" included)

The "Quercus" subgenus "Cyclobalanopsis" is treated as a distinct genus by the [http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=2&taxon_id=108828 "Flora of China"] , but as a subgenus by most taxonomists.

The genus "Nothofagus" (Southern beeches; about 35 species from the Southern Hemisphere), formerly included in the Fagaceae, is now treated in the separate family Nothofagaceae.

Distribution

The Fagaceae are widely distributed across the Northern Hemisphere. Genus-level diversity is concentrated in Southeast Asia, where most of the extant genera are thought to have evolved before migrating to Europe and North America (via the Bering Land Bridge). [Manos, PS., AM Stanford. 2001b The historical biogeography of Fagaceae: Tracking the tertiary history of temperate and subtropical forests of the Northern Hemisphere. "International Journal of Plant Sciences" 162: S77-S93 Suppl. 6.] Members of the Fagaceae (such as "Fagus grandifolia", "Castanea dentata" and "Quercus alba" in the Northeastern United States, or "Fagus sylvatica", "Quercus robur" and "Q. petraea" in Europe) are often ecologically dominant in Northern temperate forests.

References

* [http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=10338 Flora of China: Fagaceae]
* [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=10338 Flora of North America: Fagaceae]

External links

* [http://www.topwalks.net/plants/generos/fagaceae.htm Fagaceae in Topwalks]