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following is an account of the three species into which the Quercus Robur of Linnæus has been divided:—Quercus pedunculata, Quercus sessilifiora, and Quercus lanuginosa. Brief notes are given also of certain Mediterranean and Oriental forms which are in cultivation. The generic character will be given in another part, with our description of the exotic oaks in cultivation in these islands. Plates 78 and 79 show the twigs and buds of the pedunculate and sessile oaks, as well as those of some other species which will be described in a later volume, and the leaves of the three species now treated and of some of their varieties.

Those wishing to have the latest information on the oak from a physiological point of view are referred to the late Prof. Marshall Ward's work, which contains many details on points with which we do not propose to deal.

Loudon's account of the oak, covering over 100 closely printed pages, is also well worth study, especially with regard to the numerous historical trees, the quality of the timber, and the fungi, galls, and insects which live on or attack the tree.

A large tree, attaining a height of over 100 feet and a girth of stem of 20 to 30 feet, with the main branches large, long, and irregularly bent.

Bark, when old, irregularly fissured, and gradually increasing to a thickness of two inches or more. Branchlets in winter stout, glabrous, angled, grey, with a five-angled pith and small semicircular leaf-scars, which are set obliquely on prominent leaf-cushions and show three irregular groups of leaf-traces. Buds brown, clustered at the ends of the twigs, and arranged alternately (in 2/5 order) lower on the twigs, arising at an acute angle; blunt-oval, five-angled, with numerous imbricated scales (in five rows), which are glabrous on the surface and