250 Wisconsin Academy of Sciences, Arts, and Letters, 
Cryptogramma Stelleri (Gmel.) Prantl. 
Abundant on rocks. 
Pellaea atropurpurea (L.) Link. 
Very abundant on rocks. 
Onoclea sensihilis L. 
Abundant in moist woods. 
Onoclea Struthiopteris (L.) Hoffm. 
In wet fields and transplanted on the campus of St. Clara College. 
Pteris aquilina L. 
Abundant in open woods. 
OSMUNDACEAE 
Osmunda Claytoniana L. 
Very abundant in moist woods. 
Ophioglossaceae 
Botrychium virginianum (L.) Sw. 
Common in deep woods. 
Equisetaceae 
Equisetum arvense L. 
Common everywhere on roadsides and in margins of fields. 
Equisetum hyemale L. var. rohustum (A. Br.) A. A. Eaton. 
On rocks. 
Department of Botany, 
University of Wisconsin 
