186 



TREES OF NORTH AMERICA 



A tree, occasionally 25 high, with a trunk a foot in diameter, and stout branch- 

 lets conspicuously roughened by the large elevated U-shaped leaf-scars, and marked 



by occasional pale lenticels, coated at first with thick villous pubescence, becoming 

 during their second and third years dark dull reddish purple. 



Distribution. Sand dunes on the shores of Yakutat Bay and Disenchantment 

 Bay, Alaska. 



-i ^Leaves pubescent or tomentose below. 



19. Salix Hookeriana, Hook. Willow. 



Leaves oblong to oblong-obovate, gradually narrowed and wedge-shaped or 

 rounded at the base, acute or abruptly acuminate, with short points, or rarely 

 rounded and frequently apiculate at the apex, coarsely crenately serrate, especially 

 those on vigorous shoots, or entire, when they unfold villous, with pale hairs, or 



tomentose above and clothed below with silvery white tomentum, at maturity thin 

 and firm, bright yellow-green and lustrous, nearly glabrous or tomentose on the 

 upper surface, pale and glaucous and tomentose or pubescent on the lower surface, 



