The sessile oak is a largedeciduoustree up to 40 metres (130 feet) tall,[11] in thewhite oak section of the genus (Quercus sect.Quercus) and similar to thepedunculate oak (Q. robur), with which it overlaps extensively in range. Theleaves are 7–14 centimetres (2+3⁄4–5+1⁄2 inches) long and4–8 cm (1+1⁄2–3 in) broad, evenly lobed with five to six lobes on each side and a1 cm-long (1⁄2 in)petiole. The maleflowers are grouped intocatkins, produced in the spring. Thefruit is anacorn2–3 cm (3⁄4–1+1⁄4 in) long and1–2 cm (1⁄2–3⁄4 in) broad, which matures in about six months.
Significantbotanical differences frompedunculate oak (Q. robur) include the stalked leaves, and the stalkless (sessile)acorns from which one of its common names is derived. (With the pedunculate oak, it is the acorns which are pedunculate, i.e. on stalks, while the leaves are not.) It occurs in upland areas of altitudes over 300 m (984 ft) with higher rainfall and shallow, acidic, sandy soils. Itsspecific epithetpetraea means "of rocky places".[12]Q. robur, on the other hand, prefers deeper, richer soils at lower altitude. Fertilehybrids withQuercus robur namedQuercus × rosacea are found wherever the two parent species occur and share or are intermediate in characters between the parents.[citation needed]
Charles Darwin, in Chapter II ofOn the Origin of Species, noted that the sessile and pedunculate oaks had been described as both distinct species and mere varieties depending on the authority consulted.
Sessile oak is one of the most important species in Europe both economically and ecologically. Oak timber is traditionally used for building, ships and furniture. Today the best woods are used for qualitycabinetmaking,veneers andbarrel staves.[15] Rougher material is used forfence construction, roof beams and specialist building work. The wood also has antimicrobial properties.[16][17] It is also a goodfuel wood. During autumns with good acorn crops (the mast years), animals are traditionally grazed under the trees to fatten them.[18]
Known as "Wales's national tree", the Pontfadog Oak was a sessile oak considered to be the oldest oak tree in the UK. Located nearChirk in North Wales, its girth was measured as over 16 metres (53 ft) in 1881 and it was understood to be over 1,200 years old, an age that was due to regularpollarding for much of its life. The hollow trunk had a girth of 12.9 m (42 ft 5 in).[19]
The tree was lost in April 2013 when it blew down in high winds.[20] However,the Crown Estate propagated a sapling from the original tree and planted it inWindsor Great Park.[21] A further five saplings have been cloned from the Pontfadog Oak, three of which will be planted at theNational Botanic Garden of Wales, with the other two going to sites near Pontfadog; one atChirk Castle and the other atErddig, as part of a woodland memorial to those who died during theCOVID-19 pandemic.[22]
^Mitchell, Alan (1974). "Field Guide to the Trees of Britain and Northern Europe (Collins Field Guide)", HarperCollins Distribution Services, New York.ISBN0002120356.
^Bullock, J.A. 1992. Host Plants of British Beetles: A List of Recorded Associations – Amateur Entomologists' Society (AES) publication volume 11a: A supplement to A Coleopterist's Handbook.
^Munir, Muhammad; Aviat, Florence; Lepelletier, Didier; Pape, Patrice Le; Dubreil, Laurence; Irle, Mark; Federighi, Michel; Belloncle, Christophe; Eveillard, Matthieu; Pailhoriès, Hélène (1 October 2020). "Wood materials for limiting the bacterial reservoir on surfaces in hospitals: would it be worthwhile to go further?".Future Microbiology.15 (15):1431–1437.doi:10.2217/fmb-2019-0339.PMID33156723.S2CID226276130.
