FERN FAMILY 



35 



P. densa Hook. Oregon Cliff-brake. Stalks densely 

 tufted, 2 to 9 in. long, chestnut-brown, 

 slender and wiry. Fronds bright green, 

 1 to 3 in. long, 1 to 1^4 m - wide at base, 

 triangular or ovate, 3-pinnate below; seg- 

 ments Y\ to H in. long, linear-lanceolate, 

 sharp-tipped, margins narrowly recurved 

 in fertile fronds and edged with distinct 

 indusia, the rare sterile fronds sharply 

 toothed. {Crypto gramma densa T>ie\s.) 

 The Oregon Cliff-brake is commonly 

 found in the clefts of rocks along the Yosemite walls and 

 northward through the Sierra Nevada into Oregon. In 

 altitude it extends from the foothills to at least 8000 ft. It 

 was noted near Bridal Veil Falls, Ledge Trail, Nevada Falls, 

 etc. It is at once recognized by its dense clusters of small, 

 fertile, triangular fronds, the segments 

 of which are very narrow and crowded. 



8. CRYPTOGRAMMA. Rock-brake. 



1. C. acrostichoides R. Br. Ameri- 

 can Rock-brake. Stalks densely clus- 

 tered, straw-like, 2 to 4 in. long, those 

 bearing fertile fronds much longer. 

 Fronds 2 to 4 in. long, 2 to 3-pinnate; 

 sterile fronds with narrowly winged 

 rachises, their ovate or obovate seg- 

 ments decurrent and toothed; seg- 

 ments of the fertile fronds stalked, 

 oblong-linear, pod-like through the 

 recurving of the margins, which thus 

 form continuous indusia. Sori on the 

 backs of free veins, oblong, at length 

 running together and covering the 

 back of the segment. 



Under the edges of rocks on open 

 summits and along cliffs this Rock- 

 brake may be found. Its intense 

 green and differentiated fertile fronds 

 separate it from other ferns of this 

 region. Magnificent specimens were 

 collected on Sentinel Dome. It is also 

 found on Clouds Rest and other high 

 points. 



