1272 The Trees of Great Britain and Ireland 



to 1 in. wide, with tomentose scales, reflexed from near their bases, long and linear 

 in the upper ranks, ovate and short elsewhere, but very variable in length and 

 shape. 



This species has a remarkable distribution, occurring both in Algeria and in the 

 eastern Caucasus and northern Persia. The characters, upon which Pomel tried 

 to separate the Algerian tree as a distinct species, are unreliable. As seen, however, 

 in cultivation and described by travellers in the wild state, the Caucasian or typical 

 form is characterised by its short trunk and widely spreading horizontal branches, 

 with a bark darker in colour and smoother than in the Algerian form. The latter 

 is narrowly pyramidal in habit, with ascending branches, and with a deeply 

 furrowed whitish bark. 



This species is restricted in the Caucasus to the province of Talysch, where it 

 grows in the forests from sea- level to 4000 ft. In Persia it is met with in the 

 mountains south of the Caspian Sea. In Algeria it is less widely spread than 

 Q. Mirbeckii, being confined to the forests in the mountains near the coast from 

 Kabylia to the borders of Tunis. This oak near El Snab forms a wood at 600 ft. 

 above sea-level ; but elsewhere it is usually a tree of higher levels, occurring in the 

 Akfadou forest between 3700 and 5000 ft., where it is mixed with Q. Mirbeckii, but 

 is less abundant (Plate 323). On the northern slope of Mt. Babor, Q. castanece- 

 folia grows in company with Abies numidica and Cedrus atlantica. 



Q. castanecefolia is the southern representative of Q. Cerris in the same 

 way as Q. Mirbeckii replaces Q. sessilifiora ; and the mixed oak forests in Algeria 

 closely resemble, in their composition, the forests in Servia where the Turkey 

 oak and the sessile oak are mingled together. 



In the forest of Akfadou and elsewhere, on the line of contact between the cork 

 oaks of the lower elevations and the mixed forest of Q. Mirbeckii and Q. castanecefolia 

 higher up, the latter species and Q. Suber form hybrids which are readily distinguishable 

 in winter, as in that season Q. castanecefolia has lost its leaves, while the hybrids are 

 subevergreen and are different from Q, Suber in their inferior corky bark and in the 

 shape of the leaves. These hybrids, 1 which bear a striking resemblance to those of 

 the Turkey oak and Q. Suber, are very variable in the character of the bark, in the 

 period of fall of the leaves, and in the stature and growth of the trees. Those 

 which are closest to Q. castanecefolia in these characters have been named Q. numidica, 

 Trabut; 2 those nearest to Q. Suber, Q. kabylica, Trabut. 2 (A. H.) 



Cultivation 



We can find no reliable information as to when or by whom this oak 

 was introduced into England, but it was not known to Loudon except from 

 description. 



The only large tree we know of in England is a fine specimen at Kew, near 

 the Palm House, which measured in 1909 about 60 ft. by 9^ ft. It produces fertile 



1 Certain cork oaks in this forest which lose their leaves in winter are also probably hybrids. 

 1 In Bull. Assoc. France Avance. Sc, 1886, p. 506, and Bull. Soc. Bot. France, xxxvi. 58, 61 (1889). 



