12 Order HYDROPTERIDALES 
Pine; Milford; Monroe canyon north of Harrison; Nebraska City; 
Nemaha; Omaha; Peru; Ponca; Plummer Ford; Plattsmouth, Royal; 
Squaw canyon; Tecumseh; Weeping Water. 
13. Woodsia. 17. 
Indusium of hair-like segments, covered by sorus; teeth of leaves 
often covering the sori. 1. W. oregana. 
Indusium of broader segments, conspicuous; teeth not revolute. 
2. W. obtusa. 
1.. Woodsia oregana D. C. Eaton. Oregon Woodsia. 
On dry bluffs in the western part of the state. Belmont; Hat Creek 
basin; Long Pine; Plummer Ford. 
2. Woodsia obtusa (Spreng.) Torr. 
Crevices of rocks mostly in the southeastern part of the state. Cal- 
laway; Emerald; Long Pine; Pawnee City. 
14. Onoclea. 19. 
1. Onoclea sensibilis L. Sensitive Fern. 
Common in low, wet soil over most of the state. Antelope county; 
Endicott; Fairbury; Franklin; Halsey; Kearney; Long Pine; Ne- 
braska City; Paddock; Plummer Ford: southwest of Valentine. 
HY DROPTERIDALES. 
1. MARSILEACE. 
15. Marsilea. 20. 
1. Marsilea vestita Hook & Grev. Marsilea, Clover Fern. 
Common locally in wet soil or shallow water throughout the state. 
Brunswick; Box Butte county; Clearwater; Deuel county; Fair- 
bury; Lincoln near the Rock Island viaduct on Holdrege street; 
Minden; Plainview; Red Cloud. 
2. SALVINIACEZ. 
16. Azolla. 21. 
1. Azolla caroliniana Willd. Azolla. 
Floating on still water or stranded on muddy banks. Dismal river 
near Plummer Ford; Blue creek in Garden county. 
