188 METASPERMAE OF THE MINNESOTA VALLEY. 
Colo. 333; Wats., Fl. Calif. II, 101; Mac., Fl. Can. II, 355 in var.; Engl. 
Prantl, Nat. Pflanz. III, 1, 43. 
N. Asia; sp. very closely related or identical. 
North America: N.S., N. Br., Q., Ont. to Saskatch- 
ewan, Brit. Col. and Vancouver; S. to Washington and Colo.; 
E. to N. Eng., N. J. and Ga. 
Minn. valley: Far N. W. district; local and rare; thick- 
ets and river banks. 
Hers.: Bailey 229, Vermilion lake; Roberts 122, 
French river. 
Corylus americana Watt. Fl. Car. 236 (1788). 
C. humilis WILLD. Berl. Baumz. 108 (1796). 
Wats. and Coult., Gray’s Man. 6 ed. 474; Britt., Fl. N. J. 222; Mac., 
Fl. Can. I, 440; Webb., Fl. Neb. 109: Upham, Fl. Minn. 127; Chap., Fl. 8. 
St. 425; Cov., Fl. Ark. 220. 
North America: Ont. to Man., Selkirks, Assiniboia 
and Cypress Hills; S. to N. Eng., N. J. and W. Fla.; W. to 
Dak., Neb. and Ark. 
Minn. valley: Forest district; not infreyuent; thickets 
and edges of woods. 
HERB.: Taylor 378, Janesville; Sheldon 507, Waseca; 
Taylor 335, Janesville; Sheldon 324, Smith’s Mills, Blue Earth 
Co.; Sheldon 467, Madison Lake, Blue Harth Co.; Ballard 228, 
Jordan, Scott Co.; Oestlund 176, Hennepin Co.; Sandberg 500, 
Goodhue Co.; Oestlund 177, Minneapolis. 
BETULA Linn. Gen. 715 (1735) em. Gaert. (1791). 
Betulaster Spacu, Ann. Sci. Nat. 2, XV, 198 (1841). 
Baillon, Hist. Pl. VI, 254; Benth. and Hook., Gen. Pl. III, 404; Du- 
rand, Ind. Gen. Phan. 380; Engler and Prantl, Nat. Pflanz. 3, I, 43 (Prantl); 
Schenck, Palaeophyt. 409. 
Living species: 85; boreal and temperate regions of 
N. hemisphere; Europe; Asia; N. America. 25 (B. and H.); 
Europe, 12; Russia, 11; N. America, 11; Canada, 9-10; S. Sts., 
8; E. Sts., 7; Rocky mts., 2; Pl. King, 4; Pl. Wheel., 2; Cali- 
fornia, 2. 
Fossil species: 40; doubtfully in the Cretaceous; 
abundant in Tertiary of polar regions and in Europe. 
Betula pumila Linn. Mant. 1, 124 (1767). 
B. grayt REGEL, Bull. Soc. Mosc. X VILI, 406 (1866). 
Wats. and Coult., Gray’s Man. 6 ed. 472; Britt., Fl. N. J. 221; Mac.,, 
Fl. Can. I, 437; Upham, Fl. Minn. 128; Engl. Prantl, Nat. Pflanz. III, 
1, 45. 
North America: Newf., Labr., Anticosti, N. S., N. Br., 
