I05 



EquiseTACE.E. — Horse-Tail Family. 



Eciuisetuiii arveiise, L. Field Horsetail. 



In low sandy soil in the Minnesota and Sioux valleys, 

 and in the Black Hills. 



Ecxuisetuiii sylvatioiiiii, L. Wood Horsetail. 

 In moist woods in the Black Hills. 



Eqiiisetuiii fluviatile, L. Swamp Horsetail. 

 In swamps in the Minnesota region. 



Equisetum robustum, A., Br. Stout Scouring-rush. 



In wet places throughout the state; less common than 

 the next. 



Equisetum laevigatuni, A., Br. Smooth Scouring- 

 rush. 



In low wet places; very abundant throughout the 

 state. 



Lycopodiace.E. — Club Moss Family. 



Lycopocliuui obscuruni, L. Ground Pine. 

 In moist woods in the Black Hills. 



SeIvAGInelIvACE^. — The Little Club Mosses. 



Selaj^'inella rupestris, (L.) Spring. Rock Selaginella. 

 On rocky slopes in the Black Hills. 



SPERMOPHYTES.— SEED BEARING PLANTS. 



GYMNOSPERM^.—GYMNOSPERMS. 



PINACE^. 



Piiius ponderosa scopuloruni, Englm. Western Yel- 

 low pine. 



Throughout the Black Hills. 



Picea Canadensis, (Mill.) B. S. P. White Spruce. 



In the Black Hills, especially in the northern part. 



