Downy Oak
Encyclopedia
Quercus pubescens, the Downy Oak or Pubescent Oak, is an oak
in the white oak section of the genus, Quercus sect. Quercus. It is native to southern Europe
and southwest Asia
, from northern Spain
(Pyrenees
) east to the Crimea
and the Caucasus
. It is also found in France and parts of central Europe.
s. It is a submediterranean species, growing from the coastline to deep in the continent. Its optimum is in the submediterranean region, characterized by hot dry summers and cold winters with little rain fall. In western and central Europe, Downy Oak is confined to areas with submediteranean microclimate (gorges, sandplains, steppe slopes) or to coastlines of former lakes.
tree
growing up to 20 m. Forest-grown trees grow tall, while open-growing trees develop a very broad and irregular crown. They are long-lived, to several hundred years, and eventually grow into very stout trees with trunks up to 2 m in diameter. Open-grown trees frequently develop several trunks. The bark very rough, light grey and divided into small flakes. Large trees develop very thick whitish bark cracked into deep furrows, similar to the Penduculate oak but lighter in colour.
The twigs are light purple or whitish, tomentose. The buds are small (3-6 mm) and blunt, light brown. The leaves
are leathery usually 4-10 cm long (rarely to 13 cm) and 3-6 cm wide, usually widest beyond the middle. The leaves group at the ends of twigs. The upper leaf surface is dark green and rough, the lower light green. Both leaf surfaces are covered with minute pubescence which is sometimes lost in older leaves by late summer. The young expanding leaves are whitish or pinkish with very soft tomentum. The leaf shape is very variable, divided into 3-7 pairs of deep or shallow lobes, which are usually divided into a few sublobes. The lobes are usually blunt, rarely sharp. The apex is usually wide and round. The base of the leaf is heart shaped, widely rounded or sometimes pointed. The petioles are 4-15 mm (rarely to 22 mm) long, stout and pubescent. The leaves are persistent late into the autumn, remaining green up to early winter. They eventually turn russet or brown and fall off.
The Quercus pubescens acorn
s are light brown to yellow, 8-20 mm long, usually thin and pointed. The acorn cups are light grey to almost white, with pointed, overlapping scales, covered with tomentum. The acorn stalks are thick and pubescent, up to 2 cm long. The acorns usually occur in groups of 2-5 on the same stalk.
are accepted by Flora Europaea:
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
in the white oak section of the genus, Quercus sect. Quercus. It is native to southern Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and southwest Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, from northern Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
(Pyrenees
Pyrenees
The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain...
) east to the Crimea
Crimea
Crimea , or the Autonomous Republic of Crimea , is a sub-national unit, an autonomous republic, of Ukraine. It is located on the northern coast of the Black Sea, occupying a peninsula of the same name...
and the Caucasus
Caucasus
The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...
. It is also found in France and parts of central Europe.
Habitat
Downy Oaks typically grow in dry, lime-rich soilSoil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s. It is a submediterranean species, growing from the coastline to deep in the continent. Its optimum is in the submediterranean region, characterized by hot dry summers and cold winters with little rain fall. In western and central Europe, Downy Oak is confined to areas with submediteranean microclimate (gorges, sandplains, steppe slopes) or to coastlines of former lakes.
Description
Quercus pubescens is a medium-sized deciduousDeciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
growing up to 20 m. Forest-grown trees grow tall, while open-growing trees develop a very broad and irregular crown. They are long-lived, to several hundred years, and eventually grow into very stout trees with trunks up to 2 m in diameter. Open-grown trees frequently develop several trunks. The bark very rough, light grey and divided into small flakes. Large trees develop very thick whitish bark cracked into deep furrows, similar to the Penduculate oak but lighter in colour.
The twigs are light purple or whitish, tomentose. The buds are small (3-6 mm) and blunt, light brown. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are leathery usually 4-10 cm long (rarely to 13 cm) and 3-6 cm wide, usually widest beyond the middle. The leaves group at the ends of twigs. The upper leaf surface is dark green and rough, the lower light green. Both leaf surfaces are covered with minute pubescence which is sometimes lost in older leaves by late summer. The young expanding leaves are whitish or pinkish with very soft tomentum. The leaf shape is very variable, divided into 3-7 pairs of deep or shallow lobes, which are usually divided into a few sublobes. The lobes are usually blunt, rarely sharp. The apex is usually wide and round. The base of the leaf is heart shaped, widely rounded or sometimes pointed. The petioles are 4-15 mm (rarely to 22 mm) long, stout and pubescent. The leaves are persistent late into the autumn, remaining green up to early winter. They eventually turn russet or brown and fall off.
The Quercus pubescens acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
s are light brown to yellow, 8-20 mm long, usually thin and pointed. The acorn cups are light grey to almost white, with pointed, overlapping scales, covered with tomentum. The acorn stalks are thick and pubescent, up to 2 cm long. The acorns usually occur in groups of 2-5 on the same stalk.
Subspecies
Three subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are accepted by Flora Europaea:
- Quercus pubescens subsp. pubescens – central and southern Europe.
- Quercus pubescens subsp. anatolica O.Schwarz – southwest Asia, southeast Europe.
- Quercus pubescens subsp. palensis (Palassou) O.Schwarz – northern Spain, Pyrenees.