194 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



XV. The Colorado Variety of the Douglas Fir (Pseudotsuga 

 Douglasii, Carr.), with Photograph. By the Assistant 

 Editor, 



In British gardens and pineta fully half-a-dozen varieties of 

 the Douglas fir occur which differ from the type in their habit 

 or in the colour of their foliage. Most of these varieties have 

 been derived from plants under cultivation, but one, the so-called 

 Colorado variety, is a well-known geographical form, while 

 another, taxifolia^ (formerly occasionally met with under the 

 varietal name Drwnmondii), which differs from the type in its 

 longer, deeper-green leaves, and in its less spreading habit, is 

 also said to occur in a wild state. ^ A third plant, formerly 

 regarded as a variety of the Douglas fir, but now raised to the 

 rank of a species, inhabits a somewhat restricted area in Southern 

 California. This is Pseudotsuga macrocarpa (Mayr), a species 

 which, according to authorities, is still rare in British coUec- 

 tions.2 



Within the last few years the form known in British nurseries 

 as the Colorado variety has received a good deal of attention 

 from planters, and it has been recommended for planting in 

 some parts of Britain* in preference to the ordinary green or, 

 as it is often called. Pacific type on account of its greater 

 hardiness of constitution ; but there are reasons why planters 

 should exercise caution in regard to the formation of extensive 

 plantations of this variety. For one thing, the ordinary green 

 or Pacific type of the tree is quite hardy enough for all parts of 



^ Pinus taxifolia (Lambert) is the oldest name of the Douglas fir. The 

 name was applied by Lambert (in 1803) to the herbarium specimen collected 

 by Menzies, the discoverer of the tree, in 1792. 



"^ In Veitch's Manual of the Coniferce (new ed., 1900), taxifolia is mentioned 

 as a " local form which has been somewhat vaguely stated to occur in Oregon 

 and Mexico, but more definite information respecting its origin is wanting." 

 In his Silva of North America, Professor Sargent takes no account oi taxifolia 

 as a geographical form. 



^ It is stated in Veitch's Manual ih&i, "with the exception of macrocarpa,''^ 

 all the varieties therein mentioned are occasionally met with in British gardens. 

 Since the publication of the Manual, however, Pseudotsuga macrocarpa has 

 been introduced into the Arboretum collection at Kew {Hand-list of Trees 

 and Shrubs grown in Arboretum, 2nd ed., 1902). A third species {P. 

 Japonica) has recently been discovered in Japan. 



* Professor Schlich (see Transactions P.S.A.S., Vol. XVII. p. 196) recom- 

 mends the Colorado variety for planting in Scotland and the north of England. 



