A deciduous tree up to 70 ft high, with slender, often pendulous branches; young shoots densely clothed with grey down. Leaves very variable in size, from 3 to 9 in. long, 11⁄2 to 41⁄2 in. wide, conspicuously and deeply lobed; the lobes four to seven on each side, oblong, rounded or pointed, the larger ones often coarsely round-toothed; dark glossy green, and with sparse, minute, starry down above; grey and felted beneath; stalk downy, 1⁄4 to 3⁄4 in. long. Fruits produced two to four together on a downy, erect stalk 1⁄2 to 11⁄2 in. long; acorn about half enclosed by a cup with appressed downy scales.
Native of S.W. Europe and Morocco; introduced, according to Loudon, in 1822. It is a very distinct and elegant oak, well marked by the deeply and pinnately lobed leaves, and by their dense, close felt beneath; when young, the leaves are covered above also with a whitish or yellowish scurf of stellate hairs and render the tree very conspicuous in early summer. The leaves show, however, much variation in size and character of lobing. In its velvety downiness it much resembles Q. macranthera, which has more but shallower lobes and very prominent and persistent bud-stipules. A closer ally is Q. frainetto, but in that species the leaves have more numerous lobes (up to ten or twelve on each side) and are larger.
Elwes and Henry recorded a tree at Clonmannon, Co. Wicklow, Eire, 66 ft high with a trunk 9 ft in girth. This tree still exists and, though the trunk is hollow, it is still a fine specimen, measuring 63 × 14 ft (1968). Other examples recorded recently are: Kew, 58 × 43⁄4 ft (1965); The Grange, Benenden, Kent, pl. 1925, 45 × 31⁄2 ft (1967); Tittenhurst, Berks, 47 × 41⁄2 ft (1963); Highclere, Hants, 53 × 6 ft (1968); Borde Hill, Sussex, 50 × 43⁄4 ft (1971); Westonbirt, Glos., 68 × 61⁄4 ft (1967); Edinburgh Botanic Garden, 48 × 31⁄4 ft (1967).
There are no distinctive cultivars of Q. pyrenaica, but the branches are sometimes rather pendulous and the garden epithet pendula is sometimes applied to these. The Westonbirt specimen mentioned above is of this nature, and there is another pendulously branched tree in Holland Park, London.
Q. pyrenaica × Q. Robur. – hybrids of this parentage occur in the wild and are said to be quite common in france around angers. they have also been noted in cultivation, e.g., at tortworth, glos.