The Ferns of Washington 



T. C. FRYE AND MABEL MCMURRY JACKSON 



(Continued from American Fern Journal, Vol. 3, No. 4, page 108, 



November-December, 1913.) 



DRYOPTERIS (ASPIDIUM). Shield Fern. 



Leaves membranous, continuous with rootstock; 

 petiole more or less covered with chaffy brown scales; 

 veins free. Sori round; indusium present, flat, cordate 

 to reniform, attached by center. (Greek dryas = an 

 oak, pteris = a fern; from the forest habitat of some 

 species.) 



A. Leaf-blades with narrow base, 1-pinnate, obovate or oblanceolate; 

 veins simple or once forked; primary leaf-divisions deeply toothed 

 or iob9i, but otherwise almDSt entire. 1. D. oreopteris. 



AA. Leaf-blades with broad base, 2-3-pinnate; veins freely forked. 

 B. Leaf-blades 2-pinnate, base slightly narrowed; leaflets deeply 



and doubly serrate. 2 - D - fili*-™**- 



BB. Leaf-blades 3-pinnate, widest at base; leaflets serrate. 



3. D. dilatata. 



1. Dryopteris oreopteris (Erhr.) Max. (Figs. 47, 

 48.) 



Leaves 1- but nearly 2-pinnate; petiole short; blade 

 12-15 inches long; obovate or oblanceolate, its lower 

 surface smooth and shining; leaflets divided nearly to 

 mid-vein, their lowest division longer than the rest; 

 veins free, seldom forked. Sori very minute, near edge 

 of divisions, on backs of veins.— Alaska to Washington; 

 Europe; Asia. 



2. Dryopteris filix-mas (L.) Schott. (Figs. 46, 49, 



50.) 



Male Fern. 



Leaf-blades broadly oblong to lanceolate, 2-pinnate, 

 slightly narrowed toward the base; leaflets oblong, 

 smooth, shining beneath, the larger ones pinnately 

 incised. Indusium convex.— Alaska to Labrador, south 

 to California, Michigan, Nova Scotia; Europe.— 1 he 

 rhizome is a well known worm medicine. 



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