24 HANDBOOK 14 8, U.S. DEPARTMENT OF AGRICULTURE 



and smooth; bark of lower trunk warm brown, shredding 

 to show orange-brown or creamy papery layers beneath; 

 both sides of Cascades, Blue Mts., se. Wash.; not reported 

 from Oreg.; type locality, "Straits of Juan de Fuca." 



western paper birch (Betula papyrifera var. 



commutata) . 

 9. Leaves somewhat heart-shaped (subcordate) at base, 

 thick; margins coarsely (sometimes doubly) toothed, usu- 

 ally not lobed; new twigs hairless or finely hairy, often 

 with a whitish "bloom," sometimes resin-dotted, becom- 

 ing shiny red-brown or grayish ; bark of lower trunk dark 

 silvery gray, peeling to show purplish or whitish, shreddy 

 laver* beneath; Waljowa Mts., ne. Oreg., Blue Mts., se. 

 Wash, type locality, Hatwai Creek, Nez Perce Co., Ida. 

 northwestern paper birch (Betula papyrifera var. 



subcordata). 



?iV 



% Pollen-producing catkins 



3 %P 



Persistent central stalks of 

 catkins, from which scales 

 and "seeds" have fallen 



Catkin scale with "see 



Pollen-producing catkins 



Seed-prod 



Tissue-papery-winged 

 "seed" (enlarged) 



Section of twig, enlarged 

 to show resin dots and 

 hairs 



Western paper birch 



Leaf, with somewhat heart- 

 shaped base 



F-494027 



Northwestern paper birch 



