135 



(c). Var. intermedium, ^aton. Aspidium Americanum, Dauenport 



(Am. Nat.). 



This is the most common form, and seems quite distinct from either 



of the above varieties. Frequent in moist woods. Other varieties 



may be found corresponding very well with the numerous named 



forms, in which English fern books abound, most of which are not 



constant and are unworthy of a separate name. 

 Aspidium. Boottii, Tuckerman. A. spinulosum, Sw., var. Boottii 



(Gray's Manual). 



Swamps. Frequent. A very distinct species. 

 Aspidium cristatum, Sw. 



Situations similar to the last. Frequent. 

 Var. Clintonianum, Eaton. 



Wenham swamp (J. H. S. and J. E.). Scarce. 

 Aspidium m.arginale, Sw. 



Roclcy places in the shade. Common. 

 Aspidium acrostichoides, Sw. (Christmas Fern.) 



Eocky woods. Common. 

 Var. incisum (Gray's Manual). 



West Newbury (W. P. Conant), Georgetown, Beverly. Occasional. 



Cystopteris fragilis, Bernh. 

 Damp rocks. Common. Often disappearing by the latter part of 

 August. 



Onoelea Struthiopteris, L. Struthiopteris Germanica, Willd. 

 (Gray's Manual.) (Ostrich Fern.) 



North Andover, near Sutton's Mills station and the Merrimac river 

 (abundant), Georgetown, Boxford. Scarce. 



Onoelea sensibUis, L. (Sensitive Fern.) 

 Moist places. Very common. 



Var. obtusilotaata (Gray's Manual, etc.). 

 Frequently met with. This is merely a fertile frond which is partly 

 sterile and is common to all species, having contracted fruiting 

 fronds or portions of fronds, as in O. Struthiopteris, Osmunda 

 (var. frondosa), Lygodium, and in Botrychium (Ophioglossaceae). 

 It is an abnormal condition and not a true variety. 



Woodsia obtusa, Torr. 



Eocky places in half shade. Eather scarce. 

 Woodsia Ilvensis, B. Br. 



Eocky hills, in exposed situations; particularly abundant in the 



vicinity of Salem. 



Dicksonia pilosiuscula, WiUd. D. punctilobula, Kunze (Gray's 

 Manual, 5th ed.). (Hay-scented Fern.) 

 Shady places in moist woods. Common. 



