An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae, having approximately 600 extant species. The common name "oak" may also appear in the names of species in related genera, notably Lithocarpus. The genus is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in Asia and the Americas.
An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae, having approximately 600 extant species. The common name "oak" may also appear in the names of species in related genera, notably Lithocarpus. The genus is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in Asia and the Americas.
The seed cones are red at pollination, then pale brown, globose and 4–8 mm diameter in their first year, expanding to full size in their second year, pointed ovoid-conic, green, then grey-green to yellow-brown at maturity, 3-7.5 cm in length. The cone scales have a flat to pyramidal apophysis, with a small prickle on the umbo. The seeds are blackish, 3–5 mm long with a pale brown 12–20 mm wing; they are released when the cones open in spring 22–24 months after pollination. The pollen cones are yellow, occasionally pink, 8–12 mm long; pollen release is in mid to late spring.
Salix alba (white willow) is a species of willow native to Europe and western and central Asia. The name derives from the white tone to the undersides of the leaves.
French
Polish
freeimages.com
CC BY-SA 2.5
