PINACE.E 475 



ping rounded scales, which are much shorter than the three- 

 lobed bract. Cones oblong, short-stalked, pendulous, maturing 

 in one season when they open and release the seeds ; bracts con- 

 spicuous, three-lobed, the middle lobe awn-like. Seed resembling 

 that of a larch, but with a pointed base ; wing large, rounded, 

 partially enveloping the seed. 



The Douglas firs were formerly placed in the genus Abies, 

 but have since been separated on account of the persistent cone- 

 scales. They may also be distinguished by their narrower leaves, 

 soft to the touch, with coloured bases, and the beech-like buds. 

 The cones with their persistent scales and trident-like bracts are 

 easily recognized. 



Seven species of Pseudotsuga have been discovered, three 

 being natives of W.N. America, the remainder occupying a 

 limited range in W. China, Japan, and Formosa. 



The macroscopic characters of the wood resemble larch, 

 heartwood and sapwood being well marked, and the difference 

 between spring and summer wood very pronounced. The heart- 

 wood is reddish or brownish yellow, the sapwood yellow or cream. 

 Under the microscope the tracheids are seen to differ from those 

 of larch in having spiral thickening. The most important 

 commercial species is P. Douglasii, which is one of the most 

 valuable trees that have been introduced. 



The Douglas firs are raised from seeds sown in beds of well- 

 prepared soil in March or early April, the seeds being covered 

 with about ^ in. of fine soil. Small quantities of seed may be 

 sown in pots or boxes in greenhouses or frames, but the seedlings 

 so raised should be transferred to nursery borders at the earliest 

 possible date. They are very successful in Britain, where the 

 climatic conditions are moist and the soil moderately moist but 

 well drained, but they also succeed where conditions are less 

 favourable. In the West of England and in Scotland growth 

 is very rapid, and P. Douglasii has been known to add from 

 4-5 ft. to its height in a single growing season. 



Key to Pseudotsuga. 



Leaves entire at the apex. 



Branchlets pubescent. Leaves thin, flat beneath, blunt or 



sub-acute, with fragrant pine-apple odour. Cones 3 to 



4 in. long, with straight, erect bracts. — P. Douglasii. 

 Branchlets glabrous. Thicker needles, and smaller cones, 



2| in. long. — P. Douglasii, var. ccesia. 

 Branchlets variable in pubescence, often glaucous. Leaves 



thick, rounded beneath, with strong turpentine odour. 



Cones 2 to 3 in. long, with reflexed bracts. — P. glauca. 

 Branchlets variable in pubescence. Leaves thin, flat beneath, 



acuminate, ending in a cartilaginous point. Cones very 



