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.