FERN FAMILY 



33 



5 to 18 pairs (usually 10 to 12), ovate, J4 to 1 in. long (usually 

 Yz in. long), % to J / 2 in. wide when flat (folded lengthwise 

 until maturity), mostly opposite. Indusium whitish, narrow, 

 continuous. 



This Cliff-brake grows in the clefts of rocks, usually above 

 5000 ft. alt. Quantities of it may be seen on the open, ex- 

 posed summit passed over by the long trail to Nevada Falls. 

 Specimens found here and along other trails at high points 

 show a tendency to lobing and even parting of the segments, 

 as in the following species. 



2. P. breweri Eat. Stalks 2 to 3 in. long, very fragile, red- 

 dish brown and shiny. Fronds 2 to 6 in. long, 24 to 2 in. wide, 

 oblong in outline, simply pinnate; segments 6 to 12 pairs, *k 

 to 1*4 i n - long* thin, usually parted into two lanceolate obtuse 

 lobes of which the upper is the larger (lobes sometimes 3 or 

 4). Indusium broad, continuous and pale. 



Professor W. H. Brewer first collected this fern, finding it, 

 in 1863, near Sonora Pass at 7000 to 8000 ft. alt. It has been 

 collected at Mono Pass and on Mt. Dana at high altitudes, 

 and it also occurs in the Rocky Mts. The fronds are much 

 thinner than in other Pellaeas, and the stalks are exceedingly 

 fragile. 



3. P. ornithopus Hook. Bird-foot Cliff-brake. Stalks 2 to 

 10 in. long, clustered, dark-brown, shiny, stout and rigid. 

 Fronds equalling or longer than the stalks, 1 to 5 in. wide at 

 base, rigid, broadly ovate-lanceolate or triangular in outline, 



xi 

 P. ornithopus 



brachyptera 



P. wrightiana 



2 to 3-pinnate at least at the bases of the lower pinnae; pinnae 

 spreading, often rising obliquely, each with 5 to 16 pairs of 

 3-foliate (sometimes 5 to 7-foliate) secondary pinnae; seg- 

 ments \i to -h in, long, sharp-tipped, margins rolled back to 

 the midrib (in the rare sterile fronds the segments are 

 roundish). 



The resemblance of the segments to a bird's foot has given 

 rise to the common name, Bird-foot Cliff-brake. This is the 



