376 



Betulaceae 



Betula 



50 



Map 774 



Jetula nigra L. 



50 



Map 776 



Alnus incana var. amencana Reqel 



reported from St. Joseph and Tippecanoe Counties also, but these records 

 may be based upon planted trees. 



N. S. to s. Ont, southw. to Del. and Pa. and a relic colony in Ind. 



3. Betula papyrifera Marsh. (Betula alba L. var. papyrifera (Marsh.) 

 Spach.) Paper Birch. Map 773. This is a far northern species and is 

 found in Indiana only in the counties shown on the map. There are a few 

 small colonies of it and it grows in rather moist, sandy soil. 



Newf. to Alaska, southw. to n. Pa., cent. Mich., n. Ind., n. Wis., e. Nebr., 

 and Wyo. 



4. Betula nigra L. River Birch. Map 774. More or less frequent in 

 all the counties bordering the Kankakee River, on the south side of Cedar 

 Lake, Lake County, on the east shore of Lake of the Woods in Marshall 

 County, along the Tippecanoe River in White County, and more or less 

 frequent along some of the streams of the southwestern part of the state. 

 It is a common tree in a few places in the "flats" of Jackson and Scott 

 Counties. 



Mass. to Minn., southw. to Fla. and Tex. 



5. Betula pumila L. Dwarf Birch. Map 775. Restricted to the lake 

 area where it is found in bogs and marshes. Infrequent to rare. It is to 

 be noted that the under surface of the leaves of all of my specimens is 

 glaucous. 



Newf. to Wis., southw. to N. J., Ohio, and Ind. 



5a. Betula pumila var. glandulifera Regel. The variety differs from 

 the species in that the young branchlets, leaves, and bracts are covered 

 more or less with glandular dots or resinous glands. In our area, the dis- 

 tinction is not always clear since in the same clump of shrubs one can 

 often find some densely resinous specimens and others with only a minute 

 amount of resin. 



Ont. to Sask., southw. to Ind., and to se. Minn. 



6. X Betula Purpusii Schneider. (Betula lutea X pumila var. ylanduli- 



