The Ferns of Washington 47 



1. Ceropteris triangularis (Kaulf.) Under. 



(Plate 17, f. 1, 2.) 



Gold-back Fern. 



(Neurogramma triangularis Deils; Ggmnopteris tri- 

 angularis Underw.) 



Petiole 6-15 inches long, glossy, black; blade tri- 

 angular to pentagonal, 1-5 inches long, nearly as broad 

 as long, 3-pinnate; lower surface coated. with a yellow 

 to white waxy powder; lower pair of primary leaf-seg- 

 ments largest, triangular; segments rounded to obtuse 

 at tip, crenulate. Sori nearly covering under surface. 



On dry rocky slopes. British Columbia to Cali- 

 fornia and Arizona. 



1 1 . PELLAEA. 



Rock-ferns, small, tufted. Leaves 1-3-pinnate (1 

 in ours); petiole slender, brown, shining; leaflets of 

 spore-bearing leaves narrower than those of the others 



but otherwise similar. Sori marginal, covered by the 



reflexed leaf-margin. Veins clearly visible in ours. 



(Greek pellos = dark; referring to the petiole.) We 

 have only the following species. 



1. Pellaea occidentalis (Nels.) Rydb. (Plate 17, 

 f. 3, 4.) 



Rootstoek densely covered with rusty hair-like scales. 

 Petioles glabrous; blades l>^-4 inches long, oblong, 1- 

 pinnate; leaflets 2-6 pairs, not crowded, oblong, mostly 

 obtus<> ; dark-green, shining, firm and somewhat coria- 

 ceous, entire or the lower ones with one or two lobes at 

 the base; veins clearly visible. Indusium wide, wholly 

 covering sori.— South Dakota to Wyoming and Wash- 

 ington. 



12. CHEILAXTHES. Lip Febn. 



Small, tufted, rock-ferns. Leaves olive-green, 2-3- 

 pin nate, more or less hairy; terminal leaflets the larg- 



