182 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



one rises higher, to the handsome Q. semecarpijolia, a quite cold-climate 

 tree. The leaves of Q. incana are from 3 to 4 in. long by about 

 1 in. or less across when cultivated in Europe, but in a wild state 

 they are not nearly so narrow. In colour they are dark green on the 

 upper side, about the same shade as in Q. Ilex, and on the under side 

 they are of a silvery grey. My friend Mr. Gamble, whose trees of 

 Q. semecarpijolia are so well known at his Hampshire home in East Liss, 

 has been by no means equally successful with Q. incana, nor has 

 Kew fared any better with it in the open. My report on the Aldenham 

 specimen is not much more favourable. I have had it about four years, 

 and it has never had any protection other than that afforded by 

 adjoining shrubs, and showed no signs of having suffered seriously 

 from frost damage when its hardiness was severely tested in 1916-17, 

 but in February 191 9, when our glass registered i° below zero — that 

 is, 14 0 lower than the lowest recorded in London, only twelve miles 

 away — it was entirely crippled if not killed. Our plant was of bushy 

 growth and 2 ft. 6 in. high. Another plant, somewhat smaller, was 

 kindly sent me last year by the Director of Kew. Owing presumably 

 to its rarity, this oak is not mentioned by Bean at all, and there is only 

 quite a short account of it in the work of Elwes and Henry, which 

 does not disclose the date of its introduction into Europe, but I do 

 not suppose this can have been long anterior to 1910. 

 Q. injectoria, see sub Q. lusitanica. 



Q. insignis (Martins), Mexican White Oak. — I recently received 

 a small specimen of this oak from the Bureau of Plant Immigration 

 in Washington, an institution which has been doing admirable work 

 in the U.S.A. for the last six or seven years, and with which I have 

 on various occasions exchanged plants. I can find no account of 

 this deciduous oak in the works of Elwes and Henry or of Bean, 

 but as it comes from Mexico one would not prima facie expect it- to prove 

 hardy, though it would be premature for me to express an opinion on 

 the point. Choysia ternata affords proof that Mexican origin is not 

 necessarily a bar to a plant being able to weather English winters, 

 and, for the matter of that, Q. obtusata teaches the same lesson. 



I do not know of any other place where it is in cultivation in Europe. 

 The account of it which appears in the sixth annual list of New Plant 

 Introductions, Washington, is as follows : — 



" A rapid- growing tree, very different in habit from most oaks. Is quite 

 erect, reaches a height of 75 ft. and sends out large branches 30 or 40 ft. above 

 the ground. It is best suited to a warm moist climate. Acorns of most unusual 

 size." 



This passage is not couched in technical language, but in intelligi- 

 bility it compares very favourably, say, with the description given of 

 Q. mongolica in " Plantae Wilsonianae," vol. hi. pp. 230-1, from which 

 I defy anyone to form the faintest impression of any characteristics 

 of that tree except its bark. 



Q. Kelloggii (Newberry), Calif ornian Black Oak. — This takes 

 its popular name from the colour of the bark. I have been slow in 



