AEISTIDA. 151 



t 



flaxen appearance of the feathery awns of the orig- 

 inal species. In our species the awn is naked).. 

 Gray. 



1. S. Richardsonii) Richardson's Feather; no ag- 

 ricultural value. 



2.^ S. Avenacea (Black Oat Grass) is one of the 

 prairie grasses of Michigan, Illinois, Wisconsin, &c. 

 Flowers in July. 



3. S. Spnrfea (Porcupine Grass) this is another 

 prairie grass. 



4. S. Pennata (Feather Grass) one of the most 

 beautiful of the Genus Perennial. An ornamental 

 grass in gardens. 



16. ARISTIDA, Linn. Triple Awhted Geass. 



GEISTEEIC CHAEACTEE. 



Glumes unecLual, often bristle pointed. Lower 

 palet, tipped with three awns, the upper much 

 smaller ; otherwise much as in stipa. Culms branch- 

 ing ; leaves narrow, often involute. Spikelets in 

 simple or panicled racems or spikes. Grain linear. 

 (Name from arista, a beard or awn). All grow in 

 sterile, dry soil, and all ours have the awns naked 

 and persistent, and flowers late. Gray. 



1. A.'^amo5*-W5«TOa (Three Awned Grass). Found 

 on dry prairies of Illinois and in Kentucky. 



