Fagaceae

Fagaceae, the fagaceae, are a family of plants of the order Fagales that brings together some 670 accepted species of trees or shrubs native to the northern hemisphere. temperate regions are mostly deciduous, while in the tropics, many species occur as evergreen trees and shrubs. They are characterized by simple alternate leaves with pinnate venation, unisexual catkin-shaped flowers, and cup-shaped (dome) nutty fruits. Its leaves are often lobed and both petioles and stipules are usually present. Its fruits lack an endosperm and are in a scaly or spiny shell that may or may not enclose the entire nut, which may consist of one to seven seeds. In oaks, genus Quercus, the fruit is a valveless nut (generally containing one seed) called an acorn. The shell of the acorn on most oaks only forms a cup in which the nut sits. Other members of the family have completely closed nuts. The fagaceae is one of the most ecologically important families of woody plants in the northern hemisphere, as oaks form the backbone of temperate forests in North America, Europe, and Asia, and are one of the most important food for wildlife.

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 flooring, furniture, cabinets and wine barrels. The cork for wine bottle stoppers and a myriad other uses is obtained from the bark of the cork oak, Quercus suber. Chestnuts are the fruits of species of the genus Castanea. Numerous species of several genera are prominent ornamental plants and wood chips of the genus Fagus are often used to flavor beers. The nuts of some species of the Asian tropical genera Castanopsis and Lithocarpus are edible and are often used as ornamentals.

Description

Monoecious trees or shrubs, anemophilous or more rarely entomophilous, with persistent, marcescent or deciduous leaves, simple -often lobed-, alternate, with deciduous, petiolate stipules and pinnate venation. Male flowers gathered in erect or pendulous catkins, or in glomeruli, with sepaloid perianth divided into 4-6(9) lobes or laciniae, with (4)6-20(40) stamens, exserted and with free filaments. Female flowers solitary or arranged in groups of 2-3 at the base of the male inflorescences and surrounded by a dome-shaped basal involucre of welded scaly bracts, which becomes a more or less enveloping dome in the fruit or infructescence; they have the perianth with 4-8 lobes or lacinia, the inferior ovary, generally trilocular -sometimes with 6(9) locules-, with 2 seminal rudiments per locule and 6-9 styles. Monosperm fruits in walnut/endocarp achene generally with hairy interior, partially (acorn) or totally (chestnut, beechnut) surrounded, singly or in groups of 2-3, exceptionally up to 15, in a scale-shaped or spiny multibracteate cupule -or calibio-, dehiscent by valves in number equal to the number of nuts/achenes plus one. The seeds lack endosperm and are surrounded by a membraneaceous integument (episperm).

Classification

Fagaceae are divided into 2 subfamilies (Fagoideae K. Koch and Quercoideae Õrsted) and 7 genera are accepted.

Fagaceae monophyly is strongly supported by both morphological (especially fruit morphology) and molecular data.

The southern hemisphere genus Nothofagus, with its nearly 40 species, usually called the "southern beeches", was historically placed within the Phagaceae, as a sister genus to Fagus, but recent molecular evidence suggests that things are otherwise. While Nothofagus share a number of common characteristics with Fagaceae, such as a dome-shaped fruit structure, it differs significantly in others, including distinctive pollen and stipule morphology as well as having different numbers of stipules. of chromosomes. The currently accepted view of systematic botanists is to place Nothofagus within its own monogeneric family, the Notophagaceae.

Genres

• Castanea Mill., 1754 - The chestnuts; eight species and an accepted hybrid, temperate north of East Asia, southwest of Asia, southeast of Europe, Eastern North America.
• Castanopsis (D.Don) Spach, 1841, Nom. cons. - About 140 species accepted, southeast Asia.
• Chrysolepis Hjelmq., 1948 - 4 species accepted, West of the United States.
• Colombobalanus Nixon & Crepet, 1989 = Trigonobalanus Forman
• Fagus L., 1753 - Beech; 10 species and an accepted hybrid, temperate north of East Asia, southwest of Asia, Europe, Eastern North America.
• Formanodendron Nixon & Crepet, 1989 = Trigonobalanus
• Lithocarpus Blume, 1825 - About 340 species accepted, all except one in tropical Asia or temperate climate, one (L. densiflorus) in California and southwest of Oregon.
• Pasania Oerst, 1867 = Lithocarpus Blume
• Pasaniopsis Kudo, 1922 = Castanopsis (D.Don) Spach
• Quercus L., 1753 - Oaks and oaks; about 600 accepted species spread throughout the northern hemisphere, crossing the equator in Indonesia.
• Trigonobalanus Forman, 1962 - 3 species accepted, tropical southern Asia, southeast Asia and north of South America.
• Trisynsyne Baill. = Nothofagus Blume

Distribution

Fagaceae are widely distributed throughout the northern hemisphere. Diversity at the genus level is concentrated in southeast Asia, where most extant genera are thought to have evolved before migrating to Europe and North America (via the Beringian Bridge). Some members of the Phagaceae, such as Fagus grandifolia or 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.

Uses

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 flooring, furniture, cabinets, and wine barrels. Cork for bottle stoppers and a myriad other uses is made from the bark of the cork oak, Quercus suber. Chestnuts, a tasty winter food, are the fruits of species in the genus Castanea. Numerous species of various genera are prominently ornamental, and wood chips of the genus Fagus are often used to flavor beverages.