230 METASPEKMAE OF THE MINNESOTA VALLEY. 
Genera; 25; cosmopolitan; principally N. hemis- 
phere. 
Species: 1,000+; many cosmopolitan. 
HYDRASTIS Linn. Gen. ed. VI, 704 (1764). 
Baillon, Hist. Pl. I, 87; Benth. and Hook. Gen. Pl. I, 7; Engler and 
Prantl, Nat. Pflanz. 3, II, 55; Durand, Ind. Gen. Phan. 2; Gray, Ill. Gen. 47. 
Living species: 2; Northern Japan, 1; subarctic and 
Atlantic forest region of N. Amer., 1. 
Hydrastis canadensis Linn. Spec. 2 ed. 784 (1763). 
Wats. and Coult., Gray’s Man. 6 ed. 48; Britt, Fl. N. J. 40; Chap., Fl. 
S. St. 11; Upham, Fl. Minn. 20; Mac., Fl. Can. I, 27, 483; Engl. Prantl, 
Nat. Pflanz. III, 2, 55; Cov., Fl. Ark. 163; Wats., Bibl. Ind. I, 14. 
North America: W. Ont. and Niagara river to N. Y., 
N. J. and Ga.; W. to Ohio, Tenn., Minn., Mo. and Ark. 
Minn. valley: Reported from N. edge, and probably 
occurring rarely in N. forest region. 
CALTHA Linn. Gen. 463 (1787). 
Thacla SpacH, Suit. Buff. VII, 295 (1839). 
Psychrophila Gay, FI. Chile 1, 47 (1845). 
Populago Tourn. Last. 273 (1700). 
Baillon, Hist. Pl, I, 23 (sub Trollius); Benth. and Hook., Gen. Pl. I, 
6; Engler and Prantl, Nat. Pflanz. 3, I], 56; Durand, Ind. Gen. Phan. 2; 
Gray, Ill. Gen. I, 31. 
Living species: 16+; 9 (B. and H.); 10 species in 
northern, extratropical regions; 6-8 sp. Andes and Antarctic 
America, Australia and New Zealand. Russia, 4; N. America, 
4-9; Canada, 4-6; E. Sts. 1; Calif., 2; S. Sts., 1; Pl. King, 1; 
Pl. Wheel., 1; Russian Europe, 2; Rocky mts., 1-2. 
Caltha palustris Linn. Spec. 784 (1753). 
C. arctica R. Br. Parr. Ist Voy. Appx. 265 (1824). 
Wats. and Coult., Gray’s Man. 6 ed 44; Britt., Fl. N. J. 38; Upham, 
Fl. Minn. 20; Hook., Fl. Gt. Brit. 11; Trautv., Fl. Sib. 12; Regel, Fl. 
O.-Sib. I, 52; Mac., Fl. Can. I, 23: Forbes and Hems., Fl. Sin. I,-17; Led., 
Fl. Ross. I, 48; Nym., Fl. Eur.; Herd., Fl. Russ. Eur. 10; Engl. Prantl, 
Nat. Pflanz. III, 2, 56; Cov., Fl. Ark. 163; Wats., Bibl. Ind. I, 8: Hart., 
Fl. Scand. I, 174! Rothr., Alask. 442. 
Europe; N. and W. Asia and Siberia to Himalayas and 
China. 
North America: Canada throughout and N. U.S. to 
Md., Ohio, Iowa, Dak. and Mont. 
Minn. valley: Throughout at lower levels; swamps, 
sloughs, wet meadows, openings and with tamaracks. 
HeErRB.: Sheldon 780, Sleepy Eye; Sandberg 36, Can- 
non Falls; Leonard 3, Minneapolis; Herrick 17, Minneapolis, 
