''Quercus castaneifolia'', the chestnut-leaved oak, is a species of

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

in the turkey oak section ''Quercus'' sect. ''Cerris''. It is native to the

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...

and

Alborz The Alborz ( fa, البرز) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs nort ...

mountains of

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

, and resembles the closely related

Turkey Oak Turkey oak is a common name for several species of oaks and may refer to: *''Quercus cerris'', native to southeastern Europe and Asia Minor *''Quercus laevis ''Quercus laevis'', the turkey oak, is a member of the red oak group of oaks. It is n ...

in appearance.

Description

''Q. castaneifolia'' is a

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

growing up to tall, with a trunk up to in diameter (exceptionally up to 50 m tall with a trunk up to 3.5 m across). The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are long and 3–5 cm wide, with 10–15 small, regular triangular lobes on each side. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s are wind-pollinated

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...

s; the

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

is an

acorn The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and '' Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and borne ...

, maturing about 18 months after pollination, 2–3 cm long and 1.5–2 cm broad, bicoloured with an orange basal half grading to a green-brown tip; the acorn cup is 2 cm deep, densely covered in soft long 'mossy' bristles. The acorns are very bitter, but are eaten by

jay A jay is a member of a number of species of medium-sized, usually colorful and noisy, passerine birds in the Crow family, Corvidae. The evolutionary relationships between the jays and the magpies are rather complex. For example, the Eurasian m ...

s and

pigeon Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...

squirrel Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...

s usually only eat them when other food sources have been exhausted.

Cultivation

The tree was introduced to England in 1846, but remains relatively rare in collections despite being a vigorous grower. A tree from the original introduction is at the

Royal Botanic Gardens, Kew Royal Botanic Gardens, Kew is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. An internationally important botanical research and education institution, it employs 1,100 ...

, another survives at the

Harlow Carr Harlow is a large town and local government district located in the west of Essex, England. Founded as a new town, it is situated on the border with Hertfordshire and London, Harlow occupies a large area of land on the south bank of the upper ...

arboretum in

Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...

. The

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

''Quercus castaneifolia'' 'Green Spire' has been selected for its erect growth.

Notable specimens

A specimen of Quercus castaneifolia found in the Hyrcanian forest of northern Iran on 29. April 2021 by Alireza Naqinezhad is considered to be the tallest oak in the world. It has a height of 60.4m, a diameter of 4.9m, and a circumference of 22m. The finding was published in a tweet by Pieter De Frenne, professor of forestry at the faculty of Bioscience Engineering at Ghent University.

References

{{Taxonbar, from=Q1010050 castaneifolia Trees of Western Asia Trees of mild maritime climate Trees of Mediterranean climate Flora of Azerbaijan Flora of Iran Plants described in 1831