plus a long list of invalid names and another long list of names below the species level
Quercus petraea, commonly known as the sessile oak,[3]Cornish oak,[4]Irish Oak or durmast oak,[5] is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland,[6] and an unofficial emblem in Wales[7] and Cornwall.[8][9]
The sessile oak is a large deciduoustree up to 40 metres (130 feet) tall,[10] in the white oak section of the genus (Quercus sect. Quercus) and similar to the pedunculate oak (Q. robur), with which it overlaps extensively in range. The leaves are 7–14 centimetres (2+3⁄4–5+1⁄2 inches) long and 4–8 cm (1+1⁄2–3 in) broad, evenly lobed with five to six lobes on each side and a 1 cm-long (1⁄2 in) petiole. The male flowers are grouped into catkins, produced in the spring. The fruit is an acorn 2–3 cm (3⁄4–1+1⁄4 in) long and 1–2 cm (1⁄2–3⁄4 in) broad, which matures in about six months.
Significant botanical differences from pedunculate 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. Its specific epithetpetraea means "of rocky places".[11]Q. robur, on the other hand, prefers deeper, richer soils at lower altitude. Fertile hybrids with Quercus robur named Quercus × rosacea are found wherever the two parent species occur and share or are intermediate in characters between the parents.
Charles Darwin, in Chapter II of On 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.
The Welsh oak longhorn beetle (Pyrrhidium sanguineum) is named after its host tree; the larvae feed at the bark interface of dead wood.[13]
Uses
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 quality cabinetmaking, veneers and barrel staves.[14] Rougher material is used for fence construction, roof beams and specialist building work. The wood also has antimicrobial properties.[15][16] It is also a good fuel wood. During autumns with good acorn crops (the mast years), animals are traditionally grazed under the trees to fatten them.[17]
Pontfadog Oak
The Pontfadog Oak, once considered to be the oldest oak tree in the UK, was a sessile oak. This grew near Chirk in North Wales. It was understood to be over 1,200 years old, an age that was due to regular pollarding for much of its life. The hollow trunk had a girth of 12.9 m (42 ft 5 in). It was lost in April 2013 when it blew down in high winds.[18]
^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.
