26 
Colorado 
Agricultural College 
Fig. 19. Large 
Crab-grass (Syn- 
therisma sanguin- 
ale). A. Top view. 
B Bottom view. 
X 8. 
Fig. 20. Small 
Crab-grass (Syn- 
therisma humi- 
fusum). A. Bottom 
view. B. Top view. 
X IG 
1. Large Crab-Grass {Syn- 
therisma sanguinale (L.) Dulac.) 
(Fig. 19). — Seeds dark ivy green 
to Andover green in color ; twice 
as long as /S. humifusum. 
2. Small Crab-Grass {Sny- 
thcrisma humifusum (Pers.) 
Rydh.) (Fig. 20).— Seeds black 
in color ; almost as wide as long. 
6. Triple-awned Grass 
{Aristicla L.) 
The lemma tapers off into 
a terminal awn and two lat- 
eral awns as long or longer 
than the seed; palet thin, 
scaleTike ; rachilla not dis- 
tinguishable ; seed downy or 
smooth at the liase, 7-10 mm. 
long, .5-1 mm. wide, scarcely 
wider than the awns. 
Wire Grass {Aristkla 
loiifiixcta Htcud.) (Fig. 21. — 
Awns neither twisted nor 
bent ; spikelets purplish ; 
awns 10-15 mm. long; lemma 
5-12 mm. long. 
i*'ig. 
2J. Wire grass (Artistida loagiseta). x G. 
