A NEW LARCH FROM ALASKA 



By W. F. WIGHT 



LARIX ALASKENSIS Wight, sp. nov. Alaska Larch 



A small tree, attaining a maximum height of about 9 m. and a 

 diameter of 20 cm. ; leaf-fascicles at the ends of branches 3 to 5 mm. 

 long; leaves pale green, 5 to 20mm. long, about 5 mm. broad, rounded 

 on the upper surface, slightly keeled on the lower; cones borne at 

 the ends of lateral branchlets 3 to 5 mm. long, ovoid or short-oblong, 

 10 to 15 mm. long, 9 to 12 mm. broad; cone scales slightly longer 

 than broad, the larger ones 8 to 10 mm. long, 7 to 9 mm. broad, 

 rounded at the apex, abruptly contracted toward the base ; bracts of 

 the cone about one-third as long as the cone scales, ovate, acute; 

 flowers not seen. 



Distribution. — Upper Kuskokwim River to the Yukon and Tanana 

 rivers. 



Type-specimen: No. 379,803, U. S. Nat. Mus. ; collected August 

 6, 1902, at Tanana, Alaska, by A. J. Collier (no. 117). 



Larix alaskensis differs from L. laricina in its usually shorter 

 leaves, but more particularly in its cones. The cone scales are longer 

 in proportion to their breadth ; the bracts of the cone scales are ovate 

 and without a projecting mucronate point at the apex, while L. 

 laricina has bracts short-oblong to nearly orbicular in outline, and 

 commonly emarginate or lacerate on either side of a mucronate 

 projection at the apex. From L. dahurica, the most closely related 

 Asiatic species, it differs in its usually shorter leaves, in its smaller 

 cones, with the cone scales less widely spreading in dried specimens, 

 and in its narrower cone bracts. 



Betiveen the Yukon and Cook Inlet. — Upper Kuskokwim, Herron, 

 August, 1899; Tanana Valley, east of Cantwell River, Brooks & 

 Prindle, August 2y, 1902; Kaltag, on the Yukon, Collier, 1902 (no. 

 147); Tanana, Collier, 1902 (nos. 117, 118); Weare, Georgeson, 

 1900 (no. 6). 



EXPLANATION OF PLATE XVII 



a. Fruiting branch. 



b. Back of cone scale. 



c. Cone scale, with ovules. 



d. Bract of cone scale. 



e. Bract of cone scale of L. laricina. 



174 



