276 A HANDBOOK OF CONIFERS 



Foliage greenish, cone-bracts with mucro exceeding scales. 

 Leaves deeply keeled on both sides. — L. Potanini. 

 Leaves keeled beneath only. — L. occidentalis. 

 Young shoots glabrous, cones 1-1 1 in. long. 



Young shoots greyish, cone-scales not bevelled, leaves of long 



shoots up to \\ in. long. — L. europcea. 

 Young shoots shining brown, cone-scales variable in size, 



bevelled, leaves as in L. euro})CBa. — L. pendula. 

 Young shoots bright reddish brown, leaves of long shoots 

 2^-4: in. long.— Z. Principis-R^ipjwechtii. 

 Young shoots glabrous, often glaucous, cones |-| in. long. L. 

 americana. 



Larix alaskensis, Wight. ^ 

 Alaska Larch. 



Tamarack. 



This larch is described {loc. cit.) as a small tree attaining a 

 height of about 9 m. and a diameter of 20 cm. ; leaf -fascicles at 

 the ends of shoots 3-5 mm. long ; leaves pale green, 5-20 mm. 

 long, about 5 mm. broad, rounded on the upper surface, slightly 

 keeled on the lower ; cones borne at the ends of lateral branchlets, 

 3-5 mm. long, ovoid or short oblong, 10-15 mm. long, 9-12 mm. 

 broad ; cone-scales slightly longer than broad, the larger ones 

 8-10 mm. long, 7-9 mm. broad, rounded at the apex, abruptly 

 contracted towards the base ; bracts of the cone about one-third 

 as long as the cone-scales, ovate, acute, without a projecting 

 mucro ; flowers not seen. 



Judging from the description and figure, this larch is closely 

 related to L. americana, and may be merely a geographical form 

 of it distinguished by its usually shorter leaves, and the relatively 

 large cone scales, which have shorter and broader bracts without 

 a projecting mucro. 



It is distributed from the Upper Kuskokwim River to the 

 Yukon and Tanana Rivers, Alaska. 



R. S. Kellogg, in an account of the Forests of Alaska, ^ says 

 this larch grows sparingly in the river and creek valleys of the 

 region named and is seldom more than 30 ft. high. It occurs 

 with white spruce, white birch, balsam poplar, black cottonwood, 

 black spruce, and aspen. In reference to the Alaska larch he 

 says : " Naturally, it is impossible for timber to grow rapidly or 

 to large sizes in soil which is perpetually frozen. On such sites 

 the roots can penetrate only the overlying cover of moss and 

 humus, and must spread out flat upon the frozen layer beneath. 

 Rapid and thrifty growth has taken place only upon warm 



^Smithsonian Misc. Coll. L., pt. 2, p. 174 (1907). 

 2 Forest Service Bull. (U.S.A. Dept. Agric), 81. 



