52 UNIVERSITY OF MISSOURI STUDIES [2OO 



Order 3. EQUISETALES. 

 Family 3. EQUISETACEAE Michx. Horsetail family. 



11. EQUISETITM L. HORSETAIL. 



14. E. arvense L. FIELD HORSETAIL. 



Swales and shores of streams; sandy moist meadows, 5100- 

 10000 ft. (Daniels, 260). 



NORTH AMERICA: EUROPE: ASIA. 



15. E. laevigatrim A. Br. SMOOTH SCOURING RUSH. 



Along streams and railway embankments in the plains 

 and on the mountains, 5100-12500 ft. (Daniels, 392). 



NEW JERSEY to BRITISH COLUMBIA; NORTH CAROLINA to 

 MEXICO and CALIFORNIA. 



Order 4. LYCOPODIALES. 

 Family 4. LYCOPODIACEAE Michx. Clubmoss family. 



12. LYCOPODITJM L. CLUBMOSS. 



16. L. annotiimm L. STIFF CLUBMOSS 



Under dwarf and procumbent shrubs, hidden almost com- 

 pletely from view, Arapahoe Peak, above timberline, nooo- 

 11500 ft. (Daniels, 879). 



LABRADOR to ALASKA; WEST VIRGINIA to COLORADO and 

 WASHINGTON: EUROPE: ASIA. 



Family 5. SELAGINELLACEAE Underw. Selaginella 

 family. 



13. SELAGINELLA Beauv. LITTLE CLUBMOSS. 



17. S. densa Rybd.fS. Engelmanni Hieron.] DENSE SELA- 

 GINELLA. 



Forests, Redrock lake, 10100 ft. (Ramaley & Robbins). 

 SOUTH DAKOTA to MONTANA ; NEBRASKA to COLORADO. 



17^. S. TInderwoodii Hieron. [S. rupestris Fendleri Un- 

 derw.]. UNDERWOOD'S SELAGINELLA. 



Common on exposed rocks, 6000-8100 ft. (Daniels, IS 1 )- 

 Redrock lake 10100 ft. (Ramaley and Robbins). 



COLORADO to NEW MEXICO. 



