| Pedunculate Oak | |
|---|---|
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| Leaves and acorns (note the long acorn stems). | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Plantae |
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Fagales |
| Family: | Fagaceae |
| Genus: | Quercus |
| Section: | Quercus |
| Species: | Q. robur |
| Binomial name | |
| Quercus robur L. |
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Quercus robur (sometimes considered Q. pedunculata or "Q. robur") is commonly known as the Pedunculate Oak or English oak. It is native to most of Europe, and to Asia Minor to the Caucasus, and also to parts of North Africa.
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Taxonomy
Q. robur (Latin quercus, "oak" + robur "strength, hard timber") is the type species of the genus (the species by which the oak genus Quercus is defined), and a member of the white oak section Quercus section Quercus. The populations in Italy, southeast Europe, and Asia Minor and the Caucasus are sometimes treated as separate species, Q. brutia Tenore, Q. pedunculiflora K. Koch and Q. haas Kotschy respectively.
A close relative is the Sessile Oak (Q. petraea), which shares much of its range. Q. robur is distinguished from this species by its leaves having only a very short stalk 3–8 mm long, and by its pendunculate acorns. The two often hybridise in the wild, the hybrid being known as Quercus × rosacea.
Description
Q. robur is a large deciduous tree 25–35 m tall (exceptionally to 50 m), with lobed and nearly sessile (very short-stalked) leaves 7–14 cm long. Flowering takes place in mid spring, and their fruit, called acorns, ripen by the following autumn. The acorns are 2–2.5 cm long, pedunculate (having a peduncle or acorn-stalk, 3–7 cm long) with one to four acorns on each peduncle.
It is a long-lived tree, with a large widespreading crown of rugged branches. While it may naturally live to an age of a few centuries, many of the oldest trees are pollarded or coppiced, both pruning techniques that extend the tree's potential lifespan, if not its health. A specimen of notable longevity is one in Stelmužė, Lithuania which is believed to be approximately 1,500 years old, possibly making it the oldest oak in Europe; another specimen, called the 'Kongeegen' ('Kings Oak'), estimated to be about 1,200 years old, grows in Jaegerspris, Denmark. Yet another can be found in Kvilleken, Sweden, .It is over 1,000 years old and 14 meters around.[1] Of maiden (not pollarded) specimens, one of the oldest is the great oak of Ivenack, Germany. Tree-ring research of this tree and other oaks nearby gives an estimated age of 700 to 800 years old. Also in Lincolnshire, England is estimated to be 1,000 years old making it the oldest in the UK, although there is Knightwood Oak in the New Forest which is also said to be as old.
Ecological importance
Within its native range Q. robur is valued for its importance to insects and other wildlife. Numerous insects live on the leaves, buds, and in the acorns. The acorns form a valuable food resource for several small mammals and some birds, notably Eurasian Jays Garrulus glandarius. Jays were overwhelmingly the primary propagators[2] of oaks before humans began planting them commercially, because of their habit of taking acorns from the umbra of its parent tree and burying it undamaged elsewhere. Mammals, notably squirrels who tend to hoard acorns and other nuts most often leave them too abused to grow in the action of moving or storing them.
Commercial Forestry
Quercus robur' is planted for forestry, and produces a long-lasting and durable heartwood, much in demand for interior and furniture work. The wood of Q. robur is identified by a close examination of a cross-section perpendicular to fibres. The wood is characterised by its distinct (often wide) dark and light brown growth rings. The earlywood displays a vast number of large vessels (~0.5 mm diameter). There are rays of thin (~0.1 mm) yellow or light brown lines running across the growth rings. The timber is around 720kg per cubic meter in density[3].
Cultivars and hybrids
A number of cultivars are grown in arboreta and in parks and gardens. The most common cultivar is Quercus robur 'Fastigiata', and is the exception among Q. robur cultivars which are generally smaller than the standard tree, growing to between 10-15 m and exhibit unusual leaf or crown shape characteristics.
- Quercus robur 'Fastigiata' ("Cypress Oak"), probably the most common cultivated form, it grows to a large imposing tree with a narrow columnar habit. The fastigiate oak was originally propagated from an upright tree that was found in central Europe.
- Quercus robur 'Concordia' ("Golden Oak"), a small very slow-growing tree, eventually reaching 10 m, with bright golden-yellow leaves throughout spring and summer. It was originally raised in Van Geert's nursery at Ghent in 1843.
- Quercus robur 'Pendula' ("Weeping Oak"), a small to medium sized tree with pendulous branches, reaching up to 15 m.
- Quercus robur 'Purpurea' is another cultivar growing to 10 m, but with purple coloured leaves.
- Quercus robur 'Filicifolia' ("Cut-leaved Oak") is a cultivar where the leaf is pinnately divided into fine forward pointing segments.
Along with the naturally occurring Q. × rosacea, several hybrids with other white oak species have also been produced in cultivation, including Turner's Oak Q. × turnerii, Heritage Oak Q. × macdanielli, and Two Worlds Oak Q. × bimundorum, the latter two developed by nurseries in the United States.
- Q. × bimundorum (Q. alba × Q. robur) (Two Worlds Oak)
- Q. × macdanielli (Q. macrocarpa × Q. robur) (Heritage Oak)
- Q. × rosacea Bechst. (Q. petraea x Q. robur), a hybrid of the Sessile Oak and English Oak. It is usually of intermediate character between its parents, however it does occasionally exhibit more pronounced characteristics of one or the other parent.
- Q. × turnerii Willd. (Q. ilex × Q. robur) (Turner's Oak), a semi-evergreen tree of small to medium size with a rounded crown; it was originally raised at Mr. Turner's nursery, Essex, UK, in 1783. An early specimen is at the Royal Botanic Gardens, Kew.[4]
- Q. × wareii (Q. robur fastigiata x Q. bicolor), a hybrid between Upright English Oak and the Swamp White Oak. The Selections within this hybrid include the (Regal Prince) 'Long'[1] cultivar and the (Kindred Spirit) 'Nadler' cultivar see Kindred Spirit Hybrid Oak with photos...International Oak Society Link
Symbolism
In England, the Pedunculate oak has assumed the status of a national emblem. This has its origins in the oak tree at Boscobel House, where the future King Charles II hid from his Parliamentarian pursuers in 1650 during the English Civil War; the tree has since been known as the Royal Oak. This event was celebrated nationally on 29th May as Oak Apple Day, which is continued to this day in some communities[5]. ‘The Royal Oak’ is the third most popular pub name in Britain (541 in 2007)[6] and has been the name of eight major Royal Navy warships. The naval associations are strengthened by the fact that oak was the main construction material for sailing warships. The Royal Navy was often described as ‘The Wooden Walls of Old England’[7] (a paraphrase of the Delphic Oracle) and the Navy’s official quick march is ‘Heart of Oak’. Furthermore, the oak is the most common woodland tree in England[8]. An oak tree has been depicted on the reverse of the pound coin (the 1987 issue) and a sprig of oak leaves and acorns is the emblem of the National Trust.
Oak leaves with acorns are depicted on the reverse of the Croatian 5 lipa coin, minted since 1993.[9]
Diseases
See also
References
- ^ http://www5.h.lst.se/lansfakta/natur/u_nm/rumskullaeken.htm
- ^ Page 131, Forest and Woodland Trees in Britain, John White, 1995, Oxford University Press. ISBN 0-19-854883-4
- ^ British Oak. Niche Timbers. Accessed 19-08-2009.
- ^ http://www.rbgkew.org.uk/plants/trees/turnersoak.html
- ^ http://www.bbc.co.uk/wiltshire/moonraking/folklore_oak_apple.shtml
- ^ http://www.solihullcamra.org.uk/features_archive.htm
- ^ http://www.nmm.ac.uk/collections/explore/object.cfm?ID=MEC1924
- ^ http://www.forestry.gov.uk/pdf/frnationalinventory0001.pdf/$FILE/frnationalinventory0001.pdf
- ^ Croatian National Bank. Kuna and Lipa, Coins of Croatia: 5 Lipa Coin. – Retrieved on 31 March 2009.
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Wikimedia Commons has media related to: Quercus robur |
- Flora Europaea: Quercus robur
- Bean, W. J. (1976). Trees and shrubs hardy in the British Isles 8th ed., revised. John Murray.
- Rushforth, K. (1999). Trees of Britain and Europe. HarperCollins ISBN 0-00-220013-9.
- (French) Chênes: Quercus robur
External links
- Oaks from Bialowieza Forest (biggest oak cluster with the monumental sizes in Europe {English}
- WikiSpecies entry
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