Evergreen oak

Description

Quercus ilex, the evergreen oak, holly oak or holm oak, is a large evergreen oak native to the Mediterranean region. It takes its name from holm, an ancient name for holly. It is a member of the Cerris section of the genus, with acorns that mature in a single summer. Quercus rotundifolia was previously thought to be part of this species, but was later moved to its own. The first trees to be grown from acorns in England are still to be found within the stately grounds of Mamhead Park, Devon. From Britton & Brayley The Beauties of England and Wales (1803): The woods and plantations of Mamhead are numerous and extensive. Many of them were introduced by Mr Thomas Balle (sic), the last of that family who, on returning from the continent brought with him a quantity of cork, ilex, wainscot, oak; Spanish chestnut, acacia, and other species of exotic trees. An evergreen tree of large size, attaining in favourable places a height of 21–28 m, and developing in open situations a huge head of densely leafy branches as much across, the terminal portions of the branches usually pendulous in old trees. The trunk is sometimes over 6 m in girth. The young shoots are clothed with a close grey felt. The leaves are very variable in shape, most frequently narrowly oval or ovate-lanceolate, 4–8 cm long, 1.2–2.5 cm wide, rounded or broadly tapered at the base, pointed, the margins sometimes entire, sometimes (especially on young trees) more or less remotely toothed. When quite young, both surfaces are clothed with whitish down, which soon falls away entirely from the upper surface leaving it a dark glossy green; on the lower surface it turns grey or tawny, and persists until the fall of the leaf; the petiole is 3–16 mm long. Fruits are produced one to three together on a short downy stalk, ripening the first season; the acorns usually 12–18 mm long in the UK, the cups with appressed, downy scales. Holm oak grows in pure stands or mixed forest in the Mediterranean and often at low or moderate elevations. Quercus ilex is prevalent from Greece to certain parts of the Iberian Peninsula, where it mixes with Quercus rotundifolia, along the northern Mediterranean coastal belt. Holm oak is listed as an invasive species in the United Kingdom. Normally the tree is unable to withstand severe frost, which would prevent it from spreading north, but with climate change, it has successfully penetrated and established itself in areas north of its native range.