128 TWELFTH ANNUAL REPORT. 



BETULACE^. Birch Family. 



BETULA, Tourn. Birch. 



[B. lenta, L. (cherry birch, sweet or black birch) possibly extends west to northers 

 Mirnesota. D>\ BeZJ mentions this state as its northwestern limit. Some of the more 

 northern references under B. nigra may belong instead to this species.] 



B. liitea, Michx. f. Yellow or Gray Birch. 



Common through the north half of the state and south to Sherburne county, reach- 

 ing a hight of 75 feet and diameter of 3 or 4 feet ; rare In the Big Woods, and south- 

 east to Houston county, WinclieU. "The 49th parallel forms the average northern 

 limit of this species from Newfoundland to the Red river valley, in which it curves 

 round and runs southward." Bell. 



B. i>apyracea, Ait. Paper or Canoe Birch. Silver Birch. 



Common, often abundant, through the north half of the state, attaining an equal 

 size with the preceding ; also common, but much smaller, southeastward near the Mis- 

 sissippi river ; thence extending west, less frequent, to the Big Woods, and to Bircli 

 Cooley (plentiful), Renville county ; absent southwestward ; "found along the Assini- 

 boine valley as far west as the Qu'Appelle lakes," Bell. "The bark of this tree, to- 

 gether with that of the Arbor-vitae,ismadeuseof in innumerable ways by the Indians." 

 Roherts. 



B. nigra, L. River or Red Birch. 



Savannah portage, Douglass; White Earth reservation, Garriion; Kettle river, 

 Shumard; Blue Earth county, Nicollet; Winona county, Holzinger; abundant along the 

 Mississippi bottoms at least as far north as Minneiska, Wabasha county, Winchell. 

 Southeast. 



B. piiiiiila, L. Low Birch. "Tag Alder." 



Common through the north half of the state, and south to Minneapolis and Saint 

 Paul ; less frequent or rare farther south, to lake Pepin, Miss Manning, and Olmsted 

 county, Harrington. 



B. g^laiidiilosa, Michx. Dwarf Birch. 



Savannah river, Houghton; north shore of lake Superior, Jujii, Winchell; ridge east 

 of the Red river, Scotf. North. 



ALNUS, Tourn. Alder. 



A. viridis, DC. Green or Mountain Alder. 



North of lake Superior (common), Juni, Roberts. North. 



A. incaua, Willd., var. glauca, Regel. Speckled or Hoary Alder. Black 

 Alder. 

 Common, or frequent, through the north half of the state, and southeastward to 

 Minneapolis; less frequent thence southeast ; rare southwestward. 



A, serrulata, Ait. Smooth Alder. 

 Lapham, Winchell. Rare. Southeast. 



SALICACE^. Willow Family. 



SALIX, Tourn. Willow. Osief. 



S. Candida, Willd. Hoary Willow. 



Throughout the state, excepting far southward. Bogs, St. Croix river. Parry; Min- 



