12 



SIXTH TRIBE, ASPIDIE^. Four genera. 

 PiiEGOPTERis, Fee. '* Beech ferns." 



P. Dryopteris, Fee. " Oak-leaved fern." Cypress swamps, 

 Oregon, N. Cal. and Alaska. 



P. alpestris, Mett. "Alpine Beech fern." Webber Lake, 

 Lassen's Peak, Mt. Standford, Cal. 8,500 ft. Rare. 



AspiDiuM, Sw. " Shield ferns." 



§ 1. JSTephrodhim. Indusium kidney-shaped. 



^ Fronds membraneous, decaying in autumn. 

 A. Nevadense, Eaton. " Sierra Shield fern." 1878. (N. Sp. !) 

 Butterfly Valley, Webber Lake, and Trinity Mts., Cal. Very rare 

 and beautiful. 



A. patens, Sw. " Spreading Wood fern." Glen Loch, Sajita 

 Barbara, Cal. and Santa Catalina Mts., Ariz. 

 ^ ^ Fronds subcoriaceous, evergreen. 

 A. rigidum, S\\'. 



Var,, argutum. Eat. " Rigid Wood fern." Oakland hills. 

 Coast and Sierra foot-hills, Cal. 



A. spinulosum, Sw. " Spinulose Wood fern." 

 Var., dilatatum. " Oregon Wood fern." 

 Astoria, Coos Bay, Oregon. 



§ 2. Poly sty chum. Indusium orbicular, fixed by the centre. 



^ Fronds once pinnate. 

 A. munitum, Kaulf. " Chamisso's Shield fern." 

 Var., nudatum. Yo-Semite, Cal, 

 " imbricans. Near Shasta, Cal. 

 " ineiso-seratum. Oregon and Monterey, Cal. 

 ^ ^ Pinna nearly or quite jjinnatifid. 



A. mohrioides, Bory. " New Shasta Shield fern." Mt. Eddy, 

 Head-waters Sacramento River; near Shasta, Cal. 1879. (New 

 Species !) 



Var., scopulorum, with the above. 



A. aeuleatum, Sw. " Prickly Shield fern." 



Var.. Californicum. Santa Cruz, Cal. 



" lobatum. Coast ranges, Cal. 



" angulare. Santa Cruz, Cal. 



