Scientific Name: Quercus
Plant description: The term oak is used to refer to many tree species of the Quercus genus, native to the northern hemisphere.
The Quercus genus encompasses some 800 species frequently not well differentiated from each other and with great ease of hybridization, including deciduous and perennial species, reaching 500 species with the word oak as a common denomination. Its habitat ranges from cool areas in the north to tropical latitudes, spanning America, Asia, North Africa and Europe. North America has the largest number of oak species, with Mexico being the country with the most species (150), followed by China (100) and the United States (90). Although the oaks differ from each other, some of the characteristics that distinguish them are tiny flowers and grouped into inflorescences. The fruit is called acorn. Acorns mature in six months and have a sweet and slightly bitter taste. The bark is gray and flaky or blackish and wrinkled. The leaves are oval with a lobed outline, spirally arranged, and can be serrated or smooth. The species typical of arid lands (kermes oak, holm oak and cork oak) are evergreen, while oak, gall and oak trees, typical of more humid areas, are deciduous marcescent (they keep the leaf all winter and lose it at the beginning of the spring).
Cultivation: The best way of propagation is by seeds. Seeds quickly lose their viability if dried, so they must be kept moist and fresh. It is best to sow them as soon as they mature, they should be sown in an outdoor seedbed protected from mice and squirrels. They produce a deep primary root, so they must be planted in their final place as soon as possible, they should not remain in the nursery for more than two growing seasons. In fact, the best results are given with seeds sown in their final place.
Each acorn contains a seed, rarely 2 or 3, it takes between 6 and 18 months to mature, depending on the species. Acorns and leaves contain tannic acid that protects them from fungi and insects.
The great variety of oak species means that they are adapted to a wide variety of climates, from a Mediterranean climate with hot summers and humid winters, to arid desert-like regions and subtropical rainforests.
Uses: Oak forms a durable, tough wood, highly prized. It is used in carpentry, cooperage, manufacture of boards for pallets, parquet floors and obtaining sheets. From the bark of the cork oak, very thick and fluffy, the cork is obtained. Various species produce tannins.
The barrels in which the wines, brandy and whiskey are aged are made of oak.
Oak leaves and bark are the main parts used for medicinal purposes. The juice of crushed oak leaves can be applied directly to the wounds and the leaves can be soaked in boiling water, strained to relieve inflammation of the eyes. It also speeds up the healing of cuts and burns. It serves as a mouthwash for bleeding gums, and gargles for sore throats. Calm diarrhea and dysentery, especially in children.
The seeds of many oak species are edible, generally cooked or dried and mixed with cereals to make bread or broths, although they can also be eaten raw. Some varieties such as white oak berry have a sweet and pleasant taste, but most have a bitter taste due to tannins, for this they are soaked in water for 12-24 hours several times until the water does not taste bitter.
Sometimes it has been used to replace coffee.
Oak has had great religious and cultural symbolic content for many cultures for millennia.
Plagues and diseases: Sudden oak death (Phytophthora ramorum) is a water mould that can kill oaks within just a few weeks. Oak wilt, caused by the fungus Ceratocystis fagacearum (a fungus closely related to Dutch elm disease) is also a lethal disease of some oaks, particularly the red oaks. Wood-boring beetles, as well as root rot, often being discovered only when the trees come down. A considerable number of galls are found on oak leaves, buds, flowers, roots, etc., for example: oak artichoke gall, oak marble gall, oak apple gall, knopper gall, and spangle gall.
Bridget, K. (n.d.). The Best Conditions for Oak Trees. SF Gate. https://homeguides.sfgate.com/conditions-oak-trees-70839.html
colaboradores de Wikipedia. (n.d.). Roble. Wikipedia, La Enciclopedia Libre. Retrieved July 26, 2020, from https://es.wikipedia.org/wiki/Roble
EcuRed. (n.d.). Roble - EcuRed. Retrieved July 26, 2020, from https://www.ecured.cu/Roble
NC State university. (n.d.). Quercus (Oak) | North Carolina Extension Gardener Plant Toolbox. North Carolina Extension Gardener. Retrieved July 26, 2020, from https://plants.ces.ncsu.edu/plants/quercus/
Wikipedia contributors. (2020, July 20). Oak. Wikipedia. https://en.wikipedia.org/wiki/Quercus
En español: Roble