482 A HANDBOOK OF CONlPER^ 



2 J in. long and 1| in. wide ; scales about l^^in. wide ; bracts with 

 the terminal portion reflexed over the scale below, with a long 

 central awn and triangular, short-pointed, lateral lobes. Seeds 

 about f in. long, dark shining brown above, mottled light brown 

 beneath. 



A native of Yunnan, W. China, where it was discovered by 

 Forrest in the Mekong Valley at 10,000 ft. altitude. Young 

 plants raised from Forrest's seeds are in cultivation at Edin- 

 burgh and at Leonardslee. 



Pseudotsuga glauca, Mayr. (Fig. 103.) 

 CoLOKADO Douglas Fir. 



Pseudotsuga Douglasii, var. glauca, Mayr; Blue-leaved Douglas Fir. 



A tree of smaller dimensions than the Oregon Douglas fir, 

 rarely exceeding 150 ft. in height. Young shoots olive-green, or 

 occasionally glaucous, becoming reddish brown with age, more 

 or less hairy or with the terminal shoots sometimes glabrous. 

 Winter buds resinous. Foliage with an odour of turpentine, 

 especially when rubbed. Leaves mostly on the upper side of the 

 shoot, more or less vertically arranged, similar to those of P. 

 Douglasii, but usually of a more glaucous hue and of thicker 

 texture, the upper surface being indistinctly grooved, the lower 

 surface convex with two distinct bands of stomata. Mature 

 cones 2-3 in. long, 1| in. broad, hght brown, composed of about 

 30 scales with reflexed bracts which are smaller than those of 

 P. Douglasii. Seeds similar to those of P. Douglasii, but with a 

 paler wing. 



P. glauca is distinguished from the Oregon Douglas fir by 

 its thicker leaves, which are glaucous in colour and convex 

 beneath, and by its smaller cones with reflexed bracts. 



The Colorado Douglas fir is found wild in the Cent. S. Rocky 

 Mountains, ranging through Montana, Colorado, Utah, Arizona, 

 New Mexico, and N. Mexico. It grows in a much drier climate 

 than the Oregon species, which is found in the moist cHmate of 

 the Pacific Coast region. The date of introduction into Europe 

 is uncertain, but it appears to have been since 1884. 



The Colorado Douglas fir is much hardier than the Oregon 

 species, being rarely injured by frost in this country. It has no 

 value for forestry purposes, however, its lack of vigour and slow- 

 ness of growth making it useless as a timber-producer. As a 

 decorative garden tree it is of value. 



A curious fact connected with this species is its comparative 

 immunity from attack in this country by the Douglas fir chermes 

 {Chermes cooky i), for although insects may be found on the tree 

 the attack is never severe. 



