Botrychium Virginianum Swz. Rattlesnake fern. Some- 

 what rare, and scattered; in rich, shady woods. 



Camptosorus rhisophyllus Link. Walking fern. Very com- 

 mon, on rocks wherever there is moss enough for roothold, and 

 protection from fire ; more luxuriantly where there is constant 

 moisture and shade. In dry time it crumples up and seems to 

 die, but after rain it unfolds its fronds and continues its growth. 



Cheilanthes lanuginosa Nutt. Woolly Lip fern. Common 

 on southern faces of exposed cliffs ; rolls up its fronds in dry 

 weather, but when moister conditions prevail, unrolls them as 

 fresh as ever. 



Cystopteris bulbifera Bernh. Bulbous Bladder fern. Very 

 common ; forming long lines of green in clefts between soft lime- 

 stone strata ; sometimes on the ground beneath, among the 

 stones. 



Cystopteris fragilis Bernh. Common Bladder fern. Rare; 

 moist shaded rocks. 



Notholaena dcalbata Kunze. Whitened Notholaena. Some- 

 what rare ; mostly in inaccessible places on southern faces of ex- 

 posed cliffs. 



Onoclea sensibilis L. Sensitive fern ; Leadwort. Very rare. 

 I have only found it twice, growing in the water flowing from 

 a small spring, its roots fastened in the crevices of the rock, and 

 without a trace of soil. 



Onoclea sensibilis var. obtusilolata Torrey. Very rare. Grow- 

 ing on the flat rock bottom of a shallow brook, the sori well 

 developed and quite numerous on the fertile frond. 



Pellaea atropurpurea Link. Purple cliff brake. One of 

 our most common ferns, growing in clefts and crevices of cliffs 

 a/nd rocks, everywhere ; sometimes on very small rocks, and 

 occasionally on the ground. It is extremely variable, its pin- 

 nules softer, greener and broader in moist, shaded situations. 



Phegopteris hexagonoptera Fee. Beech fern. Rare; wet 

 hollows in shady woods; not below 1,500 feet, 



