120 



92. Cystopteris fragilis (L.). Brittle Bladder Fern; 



Common Bladder Fern. Abundant; on rocks 

 wet or dry and occasionally in alluvial soil. 

 Throughout North America and in most parts 

 of the earth from the tropics to the Arctic Circle. 

 — Filix frag His (L.). 



The form angustata Link is a narrow form 

 from Vermont; £, dentata Hook, is a dentate 

 form reported from New York and California; 

 f. laciniata Dav. is a more deeply cut form from 

 New England ; f 4 Mackayi Lawson is from Nova 

 Scotia; £, magnasora Clute is a form with very 

 large sori, found on dry rocks in New England, 

 New York and Pennsylvania. 



93. Cystopteris montana (Lam.). Mountain Bladder 



Fern. Rare; on shaded rocks Labrador, north 

 shore of Lake Superior and Colorado to Alaska; 

 also in northern Europe and Asia. — Filix mon- 

 tana (Lam.). 



Davallia Smith. 



94. Davallia clavata Sm. Rare ; on moist rocks. 



Southern Florida; also in the West Indies. — 



Odontosoria clavata (Sm.). 



Dicksonia L'Her. 



95. Dicksonia punctilobula (Michx.). Boulder Fern; 



Hay-scented Fern; Fine-haired Mountain 

 Fern; Pasture Fern; Sweet Fern. Abundant; 

 in pastures, thickets and along roadsides, espec- 

 ially in upland regions. Georgia and Alabama 

 to Michigan and Canada — Dicksonia pilosiuscula 

 Willd. ; Dennstcedtia punctilobula (Michx.). 



The form cristata (Maxon) is a crested form 

 from Massachusetts (Demist c^dtia punctilobula 

 cristata Maxon) ; f. schizophylla Clute is a narrow 

 incised form from Connecticut. 



