116 A HANDBOOK OF CONIFERS 



covered by Douglas on the south side of the Columbia river in 

 1825 and was introduced by him in 1830. 



The wood is light, moderately strong, hard, close-grained, 

 light yellow or brownish, the sapwood rather lighter in colour 

 than the heartwood. It is easy to work, finishes with a smooth, 

 satiny surface and is one of the best of the American silver firs. 

 Amongst other uses it is employed for the interior finish of houses, 

 general carpentry and joinery, matchwood, and is a very excel- 

 lent boxwood on account of its being free from odour. Planks 

 and boards of large size free from blemishes are obtainable, and 

 as the tree is plentiful, timber is available for export as well as 

 for home use. Writing of this species. Hough ^ refers to a tree 

 he measured as being 254 ft. high, the lowest branch 176 ft. from 

 the ground ; diameter of trunk 4 ft. from the ground, 63 in. The 

 trunk was as clear and shapely as a mast, and from it eight logs 

 16 ft. long and one log 32 ft. long were cut. The upper end of the 

 topmost log (160 ft. from the ground) was 35 in. in diameter and 

 the nine logs were eventually cut into 18,142 board ft. of magni- 

 ficent clear lumber. 



A. nobilis has been extensively planted for ornamental pur- 

 poses throughout the British Isles, and it has attained large 

 dimensions in many gardens. It is not, however, a very satis- 

 factory tree in the warmer parts of the country, for it is often badly 

 injured by Chermes picea, var. bouveri, a conspicuous aphid that 

 protects itself bya white wool-like excretion. This insect punctures 

 young buds, causing the shoots to become seriously deformed 

 by large gouty swellings which obliterate the terminal buds and 

 eventually cause the death of the plant. In the early stages it is 

 possible to check the disease by frequently spraying with a paraffin 

 wash ; but trees that have become seriou,sly infected should be 

 dug up and burnt. When not injured by this insect the tree 

 is of a very attractive character, particularly when bearing its 

 large, erect, purple cones. It gives the best results when planted 

 in moist soil in mountain valleys, but it may also be expected to 

 succeed elsewhere if it can be kept free from disease. 



On the Ardverikie estate of Sir John Ramsden in Inverness- 

 shire 2 A. nobilis is the most vigorous of the several kinds of 

 conifers grown. It is free from disease and is likely to become 

 one of the most useful forest trees of the neighbourhood. It has 

 been planted extensively under forest conditions, and in 1910 we 

 noted a large number of trees 20-40 ft. high growing at altitudes 

 varying from 800-1,200 ft. The average annual rate of growth 

 of trees growing at an elevation of 1,200 ft. for a period of 

 thirty years was stated to have been 15 in. When purchasing 

 trees care should be taken that they are free from insect pests. 



^ American Woods, ix. No. 225, pp. 52-54. 



2 Kew Bull. 1910, 243-246 ; Elwes and Henry, loc. cit. iv, 786 (1909) ; Clinton- 

 Baker, Illust. Conif. ii, 19 (1909). 



