The Book of Grasses 



until the pressure of midsummer was past before giving their 



seeds to the care of Nature. 



Among other grasses of "<^^' 



late summer the Aristidas 

 are common in dry soil 

 throughout the country. 

 The English name of Three- 

 awned Grass is descriptive 

 of a peculiarity of the genus, 

 as each flowering scale bears 

 triple awns. In Poverty 

 SlIT Grass and Slender Aristida 



the outer awns of the 

 flowering scale are shorter 

 ^// than the middle awn and 



Vir , are upright, while the long 



middle awn spreads stiffly 

 at right angles to the spike. 

 When the spikelets are 

 comparatively few, as in the 

 species mentioned above, 

 these horizontally spreading 

 awns are so characteristic 

 that from them alone the 

 grasses may easily be recog- 

 nized. 



Poverty Grass (Aristida 

 dichoioma) is the smallest of 

 I I \ I the eastern Aristidas and 

 ^ m I il bears but short awns. Slen- 

 der Aristida has a slightly 

 larger flowering-head whose 

 horizontal awns are fre- 

 quently one half inch in 

 length. The panicles of 

 Purplish Aristida are long 

 and very bristly; the outer 

 awns of each flowering scale 

 nearly equal the horizontal purplish Aristida 



middle awn in length, and Aristida purpurasans 



X: 



Slender Aristida 

 Aristida gracilis 



102 



