Shafer : Vascular Flora of Allegheny County. 123 



HYSTRIX Moench. 

 ASPRELLA Willdenow. 



* H. Hystrix (Linnaeus). Bottle-brush grass. 



EQUISETACE^ Michaux. 



HORSETAIL FAMILY. 1-8. 



EQUISETUM Linnaeus. 



* E. arvense Linnaeus. Field horsetail. 



* E. sylvaticum Linnaeus. Wood horsetail. 



* E. hyemale Linnaeus. Common scouring-rush. 



* E. laevigatum Braun. Smooth scouring-rush. 



Fawn Township, on banks of Bull Creek, July, 1885. 



POLYPODIACE^ R. Brown. 



FERN FAMILY. I-5. 



POLYPODIUM Linnaeus. 



* P. vulgare Linnaeus. Common polypody. 



ADIANTUM Linnaeus. 



* A. pedatum Linnaeus. Maiden-hair fern. 



PTERIS Linnaeus. 



* P. aquilina Linnaeus. Bracken. 



CHEILANTHES Swartz. 



* C. lanosa (Michaux). Hairy lip-fern. 

 C. vestita Swartz. 



PELLiEA Link. 

 § P. atropurpurea (Linnaeus). Purple -stemmed cliff-brake. 



