50 Flora of Denver. ' 



LEMNACE>E. (Duckweed Family.) 



412. Lemna minor L. (DucK WEED.) A tiny two-leaved 

 plant that floats on the water, often making the surface of 

 small ponds green. Along the Platte. 



ALISMACE^E. (Water-Plantain Family ) 



413. Alisma Plantago L. Leaves on long stalks, plantain 

 like; umbels of flowers whorled, either simple or compound; 

 flowers white, small. Common along the Platte. Summer 

 and fall. 



414. Sagittaria variabilis ENGELM. Leaves arrow-shaped; 

 flowers delicate, white. Common in the marshes. Summer. 



NAIADA'CE^. (Pondweed Family.) 



415. Potamogeton natans L. In ponds, etc. Not com- 

 mon. Summer to fall. It grows in a small pond near Arga 

 and in several places along the Platte. 



CYPERACE/^:. (Sedge Family.) 



416. Cyperus aristatus ROTTB. Along the Platte. Sum- 

 mer. 



417. Cyperus inflexus MUHL. Dr. Smith. 



418. Sci'rpus pungens YAHL. Dr. Smith. 



419. Scirpus lacustris YAHL. Dr. Smith. 



420. Eleccharis acicularis R. BR. Dr. Smith. 



421. Eleocharis palustris R. BR. Along the Platte. 



422. Eleocharis olivacea TORR. ^ Along the Platte. 



423. Carex strammea WILLD. B. H. Smith. There are 

 many more of the genus Carex, but they have not been col- 

 lected. 



GR AMINES. (Grass Family.) 



424. Beckmannia erucaeformis HOST. Along streams. 



425. Panicum capilla're L. (OLD-WiTCH GRASS.) Intro- 

 duced. 



