PIXE FAMILY 49 



twist in the short petiole; old bark roughly ami deeply furrowed, drab or grayish; 



high Sierra and Coast mts 1. A. concolor. 



Leaves dark lustrous green, white beneath, notched at apex, usually spreading in 

 two ranks, on cone-bearing branches often blunt, curving upwards ; bark white, 



smooth or fissured into low flat ridges; north coast only 2. A. grandis. 



Cones 4 to 8 inches long, the bracts concealed or exserted; leaves ridged above and below 

 so as to be 4-sided, somewhat compressed, thicker on the uppermost branches, curving 

 upwards but not twisted, sessile; old bark deeply divided into roughly broken ridges, 



reddish brown; high Sierra and Coast mts 3. A. magnifica. 



Cones 4 to 5 inches long, the exserted bracts reflexed, usually concealing the scales; leaves 

 of lower branches flattened, distinctly grooved above; Trinity Summit to Washington. 



4. A. nobilis. 



Leaves alike all over tree; cones with conspicuous bracts, the exserted portion long and bristle- 

 like; bark light brown, smoothish; Santa Lucia Mts. only 5. A. venusta. 



1. A. concolor Lindl. & Gord. White Fir. (Fig. 9.) Forest tree 60 to 

 l.jU (ir 200 feet high, with a narrow crown uoniposed of tlat sprays and a 

 trunk naked for % to I/2 its height and 1 to 6 feet in diameter; bark smooth, 



Fi(i. 0. Abies concolor Lindl. & Gord., fruiting branch, 

 scales have fallen; c, scale and bract; d, seed. nat. size. 



a, Cone; 6, axis from which 

 and heavilv fissured into 



silvery or whitish in young trees, becuniiuu- thick 

 rouiuicd ridue-s on old* trunks and gray or drali-bniwn iu eoU)r. in section 

 showing dull brown areas separated by a coarse light-colored niesli : leaves 

 1/2 to 21/2 (coiniiKinly 1 to l^^) inches long, flat, often with a median channel 

 on upper side, or on the uppermost branches keeled, a prominent midrib 



