TO THE HISTORY OF CERTAI^T COXIFEES. 181 



var. Lowiana. Engelmana and Sargent, however, from their 

 examination of the trees in their native forests, comhine with 

 A. concolor the tree found on the Californian Sierras, and 

 variously known in gardens as Lowiana^ Parsonsiana^ or lasio- 

 carpa (not of Hooker). This is usually very different from con- 

 color proper, although in nursery seed-beds it is true that the 

 various forms run so much one into the other that, while it is 

 easy to pick out the extreme forms, the intermediate forms defy 

 precise differentiation in the young state. 



Professor Sargent and Dr. Engelmann, as already remarked, 

 consider the Colorado and the Calif orniaa trees to be specifically 

 identical. The former author, in his ' Forest Trees of North 

 America' (1881), p. 213, gives the range of the species, as he 

 understands it, as follows : — "Northern slopes of the Siskiyou 

 Mouutains, Oregon, and perhaps further north in the Cascade 

 Mountains, south along the western slope of the Sierra Nevadas 

 to the San Bernardino and San Jacinto Mountains, California, 

 along the high mountains of Northern Arizona to the MogoUon 

 Mountains, New Mexico, northwards to the Pike region of 

 Colorado, and in the Wahsatch Mountains of Utah." 



Prof, Sargent also says of it, '^ Perhaps merely a southern form 

 of the too nearly allied A, grandis^ Lindley." 



Andrew Murray also considered A^ concolor to be only a form 

 of grandis^ and arrived, at this conclusion after having seen 

 grcmdis growing on the Eocky Mountains, " The characters," he 

 writes in Gard. Chron. April 1875, p. 4G5, ** which were supposed 

 to differentiate it \concolor\ from graudls were its wliite colour, 

 the same on both sides of the leaf, its somewhat falcate form, 

 and some supposed difference in the bract. The former are 



common attributes of P. grandis in Utah, Avhere the 



hoary hue of the vegetation of the plains extends also into the 

 mountains ; and as to the more erect altitude and slightly bent 

 leaf, the variation is very slight, and occurs also in P, grandis. 



diffe 



J*, grandis 



>) 



Murray 



to depend a good deal upon the nature of the place, whether 

 near a stream or barren and exposed, the more barren the more 



wliite There were, in fact, very great differences in the 



habit of trees of P. grandis growling side by side, especially when 

 young. One would bear its leaves scattered thinly and sparingly 



