HOW TO KNOW THE GRASSES 



14a. Glumes about equal, 2 — 3 cm. long; lemma about 2 cm. long. 



Fig. 199. 



Aristida oligantha Michx. 



Annual; tufted; culms much branched, 

 30 — 50 cm. tall; leaf blades narrow, usu- 

 ally under 1 mm, wide; panicles 10 — 20 

 cm. long; glumes nearly equal, 2 — 3 cm. 

 long, sometimes 3-cleft at the tip; awns 

 4 — 7 cm. long, spreading, about equal in 

 length. The plants are wiry and almost 

 leafless, most of the height being the 

 bristly inflorescences. The sharp-point- 

 ed, 3-awned florets of this and other spe- 

 cies of Aiistida are great "crawlers." 

 The pointed and backwardly-barbed cal- 

 lus penetrates hair or clothing easily, 

 and every movement of the body of 

 the host results in the floret digging in 

 deeper, aided by the scabrous awns. 

 Forage value negligible. Dry open 

 ground. August — October. 



Figure 199 



14b. Glumes unequal, the first about 1 cm. long, the second twice as 

 long; lemma 12 — 15 mm. long. Fig. 200. 



DOGTOWN GRASS Aristida longiseta Steud. 



Perennial; in large tufts; culms 20 — 

 50 cm. tall; panicles narrow, standing 

 well above the leaves, appearing as a 

 feathery mass of long, reddish awns. 

 The awns may reach lengths of 6 — 8 

 cm. The narrow, stiff, straight leaves 

 may be mostly at the base of the plant. 

 Dogtown grass is an inferior forage spe- 

 cies. The sharp awns and pointed cal- 

 lus cause the florets to pierce the facial 

 tissues of grazing animals, causing seri- 

 ous infections and sometimes blindness. 

 Dry plains and foothills, especially on 

 thin rocky soil or bare ground. July — 

 October. 



Figure 200 Aristida fendleriana Steud. is similar 



in the panicle and spikelets, but most 

 of the leaves are crowded in dense, curly basal tufts. Widespread 

 in the Great Plains and western mountain states. 



15a. Awn bent, twisted at least near the base, firmly attached to the 

 lemma 18 



107 



