9 8 



Wyoming Experiment Station. 



comes quite a large tree. Since its 

 bark was the source of the Indian's 

 canoe it is sometimes called the "ca- 

 noe birch." Since it has also often 

 furnished the material upon which 

 letters were written, it has always 

 been of much interest. It is very 

 rare in Wyoming-, probably oc- 

 curring only in the northeastern part, 

 in the Black Hills. Here fine speci- 

 xxn. Paper Birch. Leaf mens of it are not rare, though they 



and fruit cluster (ament). seldom attain any great s j 



(2) WESTERN BIRCH. 



(Betula occidentalis Hook.) 



Description. Bark smooth, dark or bronze-colored: branches resin 

 dotted: leaves ovate or sometimes nearly round, sharply toothed, rather small 

 and thin: the very small, seed-like nut with broad wings. 



This birch occurs on many of our mountain streams, 

 usually as a mere fringe on the banks but occasionally as 

 small thickets. It attains a height of 25 to 40 feet and 

 furnishes slender poles often used for fencing as well as 

 for fuel. It need never be confused with the preceding, 

 but is less readily distinguished from the following. 



8. ALDER. 



(Alnus) 



This genus is represented by one species only, and 

 since it is of small economic value it may be treated 

 briefly. 



(1) PAPERLEAF ALDER. 

 (Alnus temafolia Nutt.) 



Description. Leaves rather large, sharply double-toothed: flowers in 

 clustered aments, developing during the summer preceding the season in 



