POLYPODIACEAE. '> 



14. BELVISIA Mirb. 



I. Belvisia septentrionalis (L.) Mirb. {Asplenium septentrionale Hofftn.) 

 On rocks, S. D. to Mont., N. M. and Ariz. — Alt. 6000-6500 ft.— Horsetooth 

 Mountain; South Boulder Canon; Arkansas Caiion. 



Order 3. SALVINIALES. 

 Family 3. MARSILEACEAE R. Br. Marsilia Family. 



I. MARSILEA L. 



I. Marsilea vestita Hook. & Grev. Wet, sandy soil. Ark. and Tex. to 

 Calif., B. C. and S. D.— Saguache {Wolf). 



Order 4. EQUISETALES. 



Family 4. EQUISETACEAE Michx. Horsetail Family. 



I. EQUISETUM L. Horsetail. 



Stems annual, copiously branching. 



Spike-bearing stems pale, soon withering; sheaths of branches 4-toothed. 



I. E. arvense. 

 Spike-bearing stems withering at apex, producing branches below ; sheaths of 

 branches 3-toothed. n. E. pretense. 



Stems perennial, evergreen ; branches few. 



Stems smoothish, 14-30-furrowed. 3. E. laevigatum. 



Stems roughened, s-io-furrowed. 4. E. variegatum. 



1. Equisetum arvense L. In sandy places, Greenl. and Va. to Calif, and 

 Alaska. — ^Alt. 5000-10,000 ft. — Fort Collins; Ouray; West Indian Creek; 

 Mancos; Bob Creek, west of Mt. Hesperus; Hotchkiss. 



2. Equisetum pratense Ehrh. Along streams, N. So. to N. J., Colo, and 

 Neb. — Alt. up to 10,500 ft. — Bob Creek, west of Mt. Hesperus. 



3. Equisetum laevigatum A. Br. Moist places, N. J. to Tex., B. C. and 

 Calif. — Alt. 4000-12,500 ft. — Gunnison; Parlin; Ft. Collins; West Spanish 

 Peak; Cucharas River, below La Veta; Wahatoya Creek; Trimble Springs; 

 Mancos; Grand Junction. 



4. Equisetum variegatum Schleich. In sandy soil, Arctic America to N. 

 Y. and Nev. — Clear Creek, near Denver (Coulter). 



Orders. ISOETALES. 



Family 5. ISOETACEAE Horan. Quillwort Family. 



I. ISOETES L. Quillwort. 



Stomata wanting ; leaves 40-60, rigid ; microspores whitish, papillose. 



1. /. paupercula. 

 Stomata present ; leaves 5-25, soft ; microspores deep brown, spinulose. 



2. I. Bolanderi. 



1. Isoetes paupercula (Engelm.) A. A. Eaton. [/. occidentalis Henderson, 

 /. lacustris paupercula Engelm.,] In lakes, always submerged ; Colo, to Calif., 

 Wash, and Ida. — Grand Lake, Middle Park. 



