KEY TO THE SPECIES OF FIRS 



1. Winter buds subglobose, Vk-Vi inch long; needles not bristle- 

 tipped ; cones without spiny-tipped bracts. 



2. Needles crowded toward the upper side of the twigs; cones 

 large and broad (31/2-9 inches long); Pacific Coast region. 

 3. Needles 4-sided, stomatiferous (covered with minute white 

 dots) on all sides and usually glaucous; bark furrowed or 

 scaly on mature trunks. 



4. Cones 4-6 inches long; bracts much longer than, and 

 covering cone scales ; needles with sharply defined groove 

 on upper surface; Washington, Oregon, and northern 



California A. procera, Noble Fir, p. 87. 



4. Cones 6-9 inches long; bracts never covering scales; 

 needles ribbed above and below. 



5. Cones with bracts inserted 



A. magnijica, California Red Fir, p. 85. 



5. Cones with bracts exserted .^ 



A. magnijica shastensis, Shasta Red Fir, p. 85. 



3. Needles flattened, dark green and lustrous above, with 2 

 distinct white bands (stomata) on lower surface; bark smooth 

 and ashy gray on mature trunks; cones 3^/2-6 inches long 

 with inserted bracts; British Columbia and Alaska to Wash- 

 ington and Oregon. . . .A. amabilis, Pacific Silver Fir, p. 83. 

 2. Needles flattened, on sterile branches spreading and not 

 crowded, often 2-ranked ; cones narrow, 2-5 inches long. 

 5. Cones with bracts inserted. 



6. Needles on lower branches H-1% inches long; cones 



dark purple, scales slightly longer than broad. 



7. Needles dark green and lustrous above with 2 distinct 



white bands (stomata) below, 2-ranked on lower 



branches; northeastern United States to northwestern 



Canada A. balsamea, Balsam Fir, p. 75. 



7. Needles stomatiferous on both surfaces, nearly erect 

 on lower branches; western. 

 8. Mature bark hard, smooth, gray; high western 



mountains A. lasiocarpa, Subalpine Fir, p. 77. 



8. Mature bark distinctly soft and corky, yellow-white; 



Colorado, Arizona, and New Mexico 



A. lasiocarpa arizonica, Corkbark Fir, p. 77. 



6. Needles P/^-S inches long; cones yellow to green-purple, 

 scales slightly broader than long ; western. 

 9. Needles distinctly 2-ranked, 1/2-2 inches long, dark 

 green above with 2 white bands of stomata below; 



Montana to British Columbia and California 



A. grandis, Grand Fir, p. 81. 



9. Needles spreading or obscurely 2-ranked, 2-3 inches 

 long, stomatiferous and pale green on both surfaces; 

 western United States . . A. concolor, White Fir, p. 79. 

 5. Cones with bracts exserted; needles Vi-l inch long; Appa- 

 lachian Mountains A. fraseri, Fraser Fir, p. 75. 



1. Winter buds ovoid, pointed, %-l inch long; needles P/i-2!4 

 inches long, flat, rigid, bristle-tipped; cones 3-4 inches long with 

 spiny bracts exserted 3/4-1% inches; California (Monterey County) 

 A. venusta, Bristlecone Fir, p. 87. 



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