106 American Fern Journal 



2-5 inches long, %-% 



inch wide; leaflets or lobes 4-6 

 pairs on each primary leaf-division, their margin toothed 

 or crenate. Indusium very inconspicuous, fringed 

 nearly to center.— British Columbia to Great Lakes, 

 south to California, Arizona and Nebraska. 



2. Woodsia scopulina Eat. (PL 7, f. 3, 4.) 



Petiole 2-4 inches long; leaf-blades hairy> ovate to 

 lanceolate, 1-2-pinnate, 3-6 inches long; leaflets 6-12 

 on each primary leaf-division, toothed to crenate. In- 

 dusium very delicate, its lobes broadest at base.— Alaska 

 to Ontario, Colorado and California. 



2. CYSTOPTERIS (FILIX). Bladder Fern. 



Leaves tufted; blade 2-3-pinnate; leaflets and large 

 lobes toothed; veins free. Sori round, on back of a 

 straight fork of a vein; indusium delicate, hood-like, 

 attached by wide base on inner side partly under the 



sorus, early opening. (Greek kystia = a bladder, pteris = 

 a fern; referring to the inflated indusium.) We have 

 only the following specie-: 



1. Cystopteris fragilis Bernh. (PI 7, j. 5, 6.) 



Leaves delicate, 3-12 inches long, blade and petiole 

 about equal in length; blade oblong to lanceolate; 

 veins free. Indusium tapering and acute on the free 



side.— Alaska to Labrador, south to California, Kansas 

 and Georgia. 



3. PHEGOPTERIS. Beech Fern. 



Med 



um-sized or small ferns. Petiole not jointed to 

 rootstock; leaf-blades ternate or 2-3-pinnate. Sori 

 small, round, on the backs of the veins below the apex; 

 indusium wanting. (Greek phegos = a beech or oak, 

 pteris - fern; probably from the lobing of the leaflets.) 



