Quercus appenina var. cylindracea (Guss. ex Parl.) Nyman
Quercus appenina var. rumelica (Griseb. & Schenk) Nyman
Quercus apula Gand. not validly published
Quercus arenaria Borbás
Quercus argentea Morogues
Quercus assimilis Gand. not validly published
Quercus asterotricha Borbás & Csató
Quercus asturica Gand. not validly published
Quercus atropurpurea K.Koch
Quercus atrosanguinea K.Koch
Quercus atrovirens Sm.
Quercus aurea K.Koch
Quercus australis A.Kern.
Quercus auzin Secondat ex Bosc.
Quercus avellanoides Vuk.
Quercus axillaris Schur
Quercus banatica Gand. not validly published
Quercus batavica Gand. not validly published
Quercus bavarica Gand. not validly published
Quercus bedoi Borbás
Quercus belgica Gand. not validly published
Quercus bellogradensis Borbás
Quercus borealis var. pilosa (Schur) Simonk.
Quercus brachycarpa Guss. ex Parl.
Quercus brevipes A.Kern.
Quercus brevipes Borbás
Quercus brutia Ten.
Quercus bruttia Borbás
Quercus castanoides Vuk.
Quercus commiserata Gand. not validly published
Quercus comptoniifolia K.Koch
Quercus concordia K.Koch
Quercus condensata Schur
Quercus coriifolia Vuk.
Quercus crispa Vuk.
Quercus croatica Gand. not validly published
Quercus cunisecta Borbás
Quercus cuprea K.Koch
Quercus cupressoides K.Koch
Quercus cupulatus Gilib. not validly published
Quercus cylindracea Guss. ex Parl.
Quercus dacica Gand. not validly published
Quercus danubialis Gand. not validly published
Quercus dilatata A.Kern.
Quercus discredens Gand. not validly published
Quercus dissecta K.Koch
Quercus emarginulata Gand. not validly published
Quercus erucifolia Steven
Quercus esthonica Gand. not validly published
Quercus estremadurensis O.Schwarz
Quercus ettingeri Vuk.
Quercus extensa (Schur) Schur
Quercus falkenbergensis Booth ex Loudon
Quercus farinosa Vuk.
Quercus fastigiata Lam.
Quercus femina Mill.
Quercus fennessii A.DC.
Quercus filicifolia A.DC.
Quercus filipendula Schloss. & Vuk.
Quercus foemida Mill.
Quercus fructipendula Schrank
Quercus frutetorum Gand. not validly published
Quercus geltowiensis K.Koch
Quercus germanica Lasch
Quercus grecescui Gand. not validly published
Quercus haas Kotschy
Quercus haerens Gand. not validly published
Quercus hentzei Petz. & G.Kirchn.
Quercus hispanica Willk.
Quercus hodginsii Lodd. ex Steud. not validly published
Quercus hohenackeri Gand. not validly published
Quercus horizontalis Dippel
Quercus hyemalis Steven
Quercus imeretina Steven ex Woronow
Quercus immodica Gand. not validly published
Quercus implicata Gand. not validly published
Quercus kunzei Gand. not validly published
Quercus kurdica Wenz.
Quercus laciniata Lodd.
Quercus lanuginosa Beck
Quercus lasistan Kotschy ex A.DC.
Quercus lentula Gand. not validly published
Quercus longaeva Salisb. not validly published
Quercus longiglans Debeaux
Quercus longipedunculata Cariot & St.-Lag.
Quercus longipes Steven
Quercus louettii Dippel
Quercus lucorum Vuk.
Quercus ludens Gand. not validly published
Quercus lugdunensis Gand. not validly published
Quercus macroloba Gand. not validly published
Quercus madritensis Gand. not validly published
Quercus malacophylla (Schur) Schur
Quercus mestensis Bondev & Gancev
Quercus microcarpa Lapeyr.
Quercus microcarpa Morogues
Quercus monorensis Simonk.
Quercus montivaga Gand. not validly published
Quercus natalis Gand. not validly published
Quercus nescensis Gand. not validly published
Quercus nigricans K.Koch
Quercus ochracea Morogues
Quercus oelandica Gand. not validly published
Quercus paleacea Desf.
Quercus palmata Vuk.
Quercus parmenteria Mutel
Quercus pectinata K.Koch
Quercus pedemontana Colla
Quercus pedunculata Ehrh.
Quercus pedunculata Hoffm.
Quercus pedunculiflora K.Koch
Quercus pendula (Neill) Lodd.
Quercus pendulina Kit.
Quercus petropolitana Gand. not validly published
Quercus pilosa (Schur) Simonk.
Quercus pilosula Gand. not validly published
Quercus pinnatipartita (Boiss.) O.Schwarz
Quercus plebeia Gand. not validly published
Quercus pluriceps Gand. not validly published
Quercus pseudopedunculata Vuk.
Quercus pseudoschorochensis Boiss.
Quercus pseudosessilis Schur
Quercus pseudotscharakensis Kotschy ex A.DC.
Quercus pulverulenta K.Koch
Quercus purpurea Lodd. ex Loudon
Quercus pyramidalis C.C.Gmel.
Quercus pyrenaica Steven
Quercus quaerens Gand. not validly published
Quercus racemosa Lam.
Quercus robur (Ten.) A. DC.
Quercus rossica Gand. not validly published
Quercus rostanii Gand. not validly published
Quercus rubens Petz. & G.Kirchn.
Quercus rubicunda Dippel
Quercus rumelica Griseb. & Schenk
Quercus salicifolia Steud. not validly published
Quercus scandica Gand. nom. not validly published
Quercus schlosseriana Gand. not validly published
Quercus scolopendrifolia K.Koch
Quercus scotica Gand. not validly published
Quercus scythica Gand. not validly published
Quercus semipinnata Gand. not validly published
Quercus sessiliflora var. condensata (Schur) Nyman
Quercus sessiliflora var. microcarpa (Lapeyr.) Nyman
Quercus sessiliflora var. pedemontana (Colla) Nyman
Quercus sessiliflora var. tcharachensis Albov
Quercus sieboldii Dippel
Quercus similata Gand. not validly published
Quercus speciensis Dippel
Quercus stilbophylla Gand. not validly published
Quercus subvelutina Schur
Quercus svecica Borbás
Quercus tanaicensis Gand. not validly published
Quercus tardiflora Czern. ex Stev.
Quercus tennesi Wesm.
Quercus tephrochlamys Gand. not validly published
Quercus tetracarpa Vuk.
Quercus tholeyroniana Gand. not validly published
Quercus thomasii Ten.
Quercus tomentosa Ehrh. ex A.DC. not validly published
Quercus tozzae Dippel
Quercus transiens Gand. not validly published
Quercus tricolor Petz. & G.Kirchn.
Quercus tristis Gand. not validly published
Quercus turbinata Kit.
Quercus urbica Gand. not validly published
Quercus vallicola Gand. not validly published
Quercus verecunda Gand. not validly published
Quercus versatilis Gand. not validly published
Quercus vialis Gand. not validly published
Quercus viminalis Bosc
Quercus virgata Martrin-Donos
Quercus volhynica Gand. not validly published
Quercus vulgaris Bubani
Quercus welandii Simonk.
Quercus wolgensis Gand. not validly published
Quercus robur, the pedunculate oak or English oak,[3][4] is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native to most of Europe and western Asia, and is widely cultivated in other temperate regions. It grows on soils of near neutral acidity in the lowlands and is notable for its value to natural ecosystems, supporting a very wide diversity of herbivorous insects and other pests, predators and pathogens.
Description
Quercus robur is a deciduous tree up to 40 metres (130 ft) tall,[5] with a single stout trunk that can be as much as 11 m (36 ft) in girth (circumference at breast height) or even 14 m (46 ft) in pollarded specimens. Older trees tend to be pollarded, with boles (the main trunk) 2–3 m (6+1⁄2–10 ft) long. These live longer and become more stout than unpollarded trees. The crown is spreading and unevenly domed, and trees often have massive lower branches. The bark is greyish-brown and closely grooved, with vertical plates. There are often large burrs on the trunk, which typically produce many small shoots. Oaks do not produce suckers but do recover well from pruning or lightning damage. The twigs are hairless and the buds are rounded (ovoid), brownish and pointed.[5][6][7]
The leaves are arranged alternately along the twigs and are broadly oblong or ovate, 10–12 centimetres (4–4+1⁄2 in) long by 7–8 cm (2+3⁄4–3+1⁄4 in) wide, with a short (typically 2–3 millimetres or 1⁄16–1⁄8 inch) petiole. They have a cordate (auricled) base and 3–6 rounded lobes, divided no further than halfway to the midrib. The leaves are usually glabrous or have just a few simple hairs on the lower surface. They are dark green above, paler below, and are often covered in small disks of spangle gall by autumn.[6]
Flowering takes place in spring (early May in England). It is wind-pollinated. The male flowers occur in narrow catkins some 2–4 cm (3⁄4–1+1⁄2 in) long and arranged in small bunches; the female flowers are small, brown with dark red stigmas, about 2 mm in diameter and are found at the tips of new shoots on peduncles 2–5 cm long.[6]
The fruits (acorns) are borne in clusters of 2–3 on a long peduncle (stalk) 4–8 cm long. Each acorn is 1.5–4 cm long, ovoid with a pointed tip, starting whitish-green and becoming brown, then black. As with all oaks, the acorns are carried in a shallow cup which can be distinctive in identifying the species.[6] It is an "alternate bearing" species, its large crops produced every other year.[8]
Q. robur is most likely to be confused with sessile oak, which shares much of its range. Distinguishing features of Q. robur include the auricles at the leaf base, the very short petiole, its clusters of acorns being borne on a long peduncle, and the lack of stellate hairs on the underside of the leaf. The two often hybridise in the wild, forming Quercus × rosacea.[5]
Turkey oak is also sometimes confused with it, but that species has "whiskers" on the winter buds and deeper lobes on the leaves (often more than halfway to the midrib). The acorn cups are also very different.[8]
It has numerous common names, including "common oak", "European oak" and "English oak". In French it is called "chêne pédonculé".[14]
The genome of Q. robur has been completely sequenced (GenOak project); the first version was published in 2016. It comprises 12 chromosome pairs (2n = 24), about 26,000 genes and 750 million bp.[15]
There are many synonyms, and numerous varieties and subspecies have been named.[16] The populations in Iberia, Italy, southeast Europe, and Asia Minor and the Caucasus are sometimes treated as separate species, Q. orocantabrica,Q. brutia Tenore, Q. pedunculiflora K. Koch and Q. haas Kotschy respectively.[citation needed]
Quercus × rosaceaBechst. (Q. petraea x Q. robur) is the only naturally-occurring hybrid,[17] but the following crosses with other white oak species have been produced in cultivation:
There are numerous cultivars available, among which the following are commonly grown:
'Fastigiata', cypress oak, is a large imposing tree with a narrow columnar habit.
'Concordia', golden oak, is a small, very slow-growing tree, eventually reaching 10 m (33 ft), with bright golden-yellow leaves throughout spring and summer. It was originally raised in Van Geert's nursery at Ghent in 1843.
'Pendula', weeping oak, is a small to medium-sized tree with pendulous branches, reaching up to 15 m (49 ft).
'Purpurea' is another small form, growing to 10 m (33 ft), with purple leaves.
'Pectinata' (syn. 'Filicifolia'), cut-leaved oak, is a cultivar where the leaf is pinnately divided into fine, forward-pointing segments.[18]
Distribution and habitat
The species is native to most of Europe and western Asia, and is widely cultivated in other temperate regions.
It is a long-lived tree of high-canopy woodland, coppice and wood pasture, and it is commonly planted in hedges. When compared to sessile oak, it is more abundant in the lowlands of the south and east of Britain, and it occurs on more neutral (less acid) soils. It is rare on thin, well-drained calcareous (chalk and limestone) soil. Sometimes it is found on the margins of swamps, rivers and ponds, showing that it is fairly tolerant of intermittent flooding.[19] Its Ellenberg values in Britain are L = 7, F = 5, R = 5, N = 4, and S = 0.[20]
Ecology
Within its native range, Q. robur is valued for its importance to insects and other wildlife, supporting the highest biodiversity of insect herbivores of any British plant (at least 400 species).[21] The most well-known of these are the ones that form galls, which number about 35. In Britain, the knopper gall is very common, and Andricus grossulariae produces somewhat similar spiky galls on the acorn cups. Also common in Britain are two types of spherical galls on the twigs: the oak marble gall and the cola nut gall. The latter are smaller and rougher than the former. A single, large exit hole indicates that the wasp inside has escaped, whereas several smaller holes show that it was parasitised by another insect, and these emerged instead. The undersides of oak leaves are often covered in spangle galls, which persist after the leaves fall.[8]
One of the most distinctive galls is the oak apple, a 4.5 cm diameter spongy ball created from the buds by the wasp Biorhiza pallida. The pineapple gall, while less common, is also easily recognised.[22]
The quantity of caterpillar species on an oak tree increases with the age of the tree,[23] with blue tits and great tits timing their egg hatching to the leaves opening.[23] The most common caterpillar species include the winter moth, the green tortrix and the mottled umber, all of which can become extremely abundant on the first flush of leaves in May, but the oak trees do recover their foliage later in the year.[8]
The acorns are typically produced in large quantities every other year (unlike Q. petraea, which produces large crops only every 4-10 years)[8] and form a valuable food resource for several small mammals and some birds, notably Eurasian jaysGarrulus glandarius. Jays were overwhelmingly the primary propagators[24] of oaks before humans began planting them commercially (and remain the principal propagators for wild oaks), because of their habit of taking acorns from the umbra of its parent tree and burying them undamaged elsewhere.[citation needed]
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 (around 0.5 mm or 1⁄64 inch in diameter). There are rays of thin (about 0.1 mm or 1⁄256 in) yellow or light brown lines running across the growth rings. The timber is around 720 kilograms (1,590 pounds) per cubic meter in density.[26]
In culture
In the Scandinavian countries, oaks were considered the "thunderstorm trees", representing Thor, the god of thunder.[27] A Finnish myth is that the World tree, a great oak which grew to block the movement of the sky, sunlight and moonlight, had to be felled, releasing its magic, thus creating the Milky Way.[28] The oak tree also had a symbolic value in France. Some oaks were considered sacred by the Gauls; druids would cut down the mistletoe growing on them. Even after Christianization, oak trees were considered to protect as lightning would strike them rather than on nearby inhabitation. Such struck trees would often be turned into places of worship, like the Chêne chapelle.[citation needed]
In 1746, all oak trees in Finland were legally classified as royal property, and oaks had enjoyed legal protection already from the 17th century.[29] The oak is also the regional tree of the Southwest Finland region.[30]
In England, the 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 29 May as Oak Apple Day, which continues to this day in some communities.[34]
Many place names in England include a reference to this tree, including Oakley, Occold and Eyke. Copdock, in Suffolk, probably derives from a pollarded oak ("copped oak").[35] 'The Royal Oak' is the third most popular pub name in Britain (with 541 counted in 2007)[36] and HMS Royal Oak 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"[37] (a paraphrase of the Delphic Oracle) and the Navy's official quick march is "Heart of Oak". In folklore, the Major Oak is where Robin Hood is purported to have taken shelter.[38]
Oak leaves (not necessarily of this species) have been depicted on the Croatian 5 lipa coin;[39][40][41] on old German Deutsche Mark currency (1 through 10 Pfennigs; the 50 Pfennigs coin showed a woman planting an oak seedling), and now on German-issued euro currency coins (1 through 5 cents); and on British pound coins (1987 and 1992 issues).
Notable trees
It is often claimed that England has more ancient oaks than the rest of Europe combined.[42] This is based on research by Aljos Farjon at the Royal Botanic Gardens, Kew, who found that there were 115 oaks (of both species) in England with a circumference of 9 m or more, compared with just 96 in Europe. This is attributed to the persistence of mediaeval deer parks in the landscape.[43] The Majesty Oak, with a circumference of 12.2 m (40 ft), is the thickest such tree in Great Britain.[44] The Brureika (Bridal Oak) in Norway with a circumference of 10.86 m (35.6 ft) (in 2018)[45] and the Kaive Oak in Latvia with a circumference of 10.2 m (33 ft) are among the thickest trees in Northern Europe.[citation needed] The largest historical oak was known as the Imperial Oak from Bosnia and Herzegovina. This specimen was recorded at 17.5 m in circumference at breast height and estimated at over 150 m³ in total volume. It collapsed in 1998.[46]
Two individuals of notable longevity are the Stelmužė Oak in Lithuania and the Granit Oak in Bulgaria, which are believed to be more than 1500 years old, possibly making them the oldest oaks in Europe; another specimen, called the 'Kongeegen' ('Kings Oak'), estimated to be about 1,200 years old, grows in Jaegerspris, Denmark.[47] Yet another can be found in Kvilleken, Sweden, that is over 1000 years old and 14 m (46 ft) around.[48] 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. Also the Bowthorpe Oak 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 that is also said to be as old. The highest density of Q. robur with a circumference of 4 m (13 ft) and more is in Latvia.[49]
In Ireland, at Birr Castle, a specimen over 400 years old has a girth of 6.5 m (21 ft), known as the Carroll Oak.[50]
^ abcStace, C.A. (2019). New Flora of the British Isles (4th ed.). Suffolk: C & M Floristics. ISBN978-1-5272-2630-2.
^ abcdMitchell, Alan (1974). A Field Guide to the Trees of Britain and Northern Europe. Glasgow: Collins. ISBN0-00-219213-6.
^Rose, Francis (2006). The Wild Flower Key. London: Frederick Warne. ISBN978-0-7232-5175-0.
^ abcdeCrawley, M.J. (2005). The Flora of Berkshire. Harpenden: Brambleby Books. ISBN0-9543347-4-4.
^Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry. Pirjo Mämmelä, Heikki Savolainenb, Lasse Lindroosa, Juhani Kangasd and Terttu Vartiainen, Journal of Chromatography A, Volume 891, Issue 1, 1 September 2000, Pages 75–83, doi:10.1016/S0021-9673(00)00624-5
^Identification of triterpene saponins in Quercus robur L. and Q. petraea Liebl. Heartwood by LC-ESI/MS and NMR. Arramon G, Saucier C, Colombani D and Glories Y, Phytochem Anal., November-December 2002, volume 13, issue 6, pages 305–310, PMID12494747
^Stace, C.A.; Preston, C.D.; Pearman, D.A. (2015). Hybrid Flora of the British Isles. Bristol: Botanical Society of Britain and Ireland. ISBN978-0-901158-48-2.
^Kennedy, C. E. J.; Southwood, T. R. E. (1984). "The number of species associated with British Trees: a re-analysis". Journal of Animal Ecology. 53 (2). Wiley, British Ecological Society: 459. doi:10.2307/4528. JSTOR4528.
^Redfern, Margaret; Shirley, Peter (2002). "British Plant Galls". Field Studies. 10: 207–531.
^Marja-Leena Huovinen; Kaarina Kanerva (1982). Suomen terveyskasvit: luonnon parantavat yrtit ja niiden salaisuudet (in Finnish). Helsinki: Valitut Palat. p. 256. ISBN951-9078-87-8.
^Nykänen, Topi (6 August 2006). "Elämänvoiman juurella". Turun Sanomat (in Finnish). Archived from the original on 2022-06-03. Retrieved 2022-06-03.
^"Pipolan tammimetsikkö". aikamatkakarjalohjalla.fi (in Finnish). Karjalohjan Kotiseutuyhdistys. 2019. Archived from the original on 2022-06-03. Retrieved 2022-06-03.
^"Tammi". Luontoportti (in Finnish). Archived from the original on 2022-06-03. Retrieved 2022-06-03.