410 WEED FLORA OP IOWA 



Tickle or Hair Grass (Pamicum capillar e L.)- 



Spikelets small, ovate or acute, one-fifteenth to one-twelftli in. 

 long, acuminate-pointed, smooth, shining; sterile glumes usually 

 absent, when present not shining ; first glume 1-3-nerved, obtuse to 



Figure 241A 



Pipire 241B 



Fig. 241. A. Tickle or Hair Grass {Panicum capillare'). At the left a spllielet 

 opened, at the right various views. A, B and C, the outer, inner and edge 

 views, respectively, of a floret. D and B are views of the spikelet, D 

 showing the second glume and the first in part, and B the first and third 

 and the second In part. F, a group showing the natural size of the pre- 

 ceding. 



B. Sprouting Crab Grass. Various views of spiltelets. 



(A, at the left, drawn by C. M. King ; A, at the right, after Hillman, Bull. Mich. 

 Agr. Bxp. Sta. ; B, drawn by C. M. King.) 



acute; second and third glumes 5-7-nerved, tips acute; flowering 

 glume shining, smooth, elliptical, obtuse, or subacute. Often found 

 in clovers and in timothy. 



Sprouting Crab Grass {Panicum proliferum Lam.). 



Spikelet lanceolate, ovate, acute, one- tenth in. in length, smooth; 

 lower glume obtuse, nerveless or 1-3-nerved ; second and third glume 

 equal, acute, 5-7-nerved ; flowering glume smooth and shining ; pedi- 

 cels scabrous. Rarely found in clover. 



Switch Grass {Panicum virgatum L.). 



Spikelets ovate, acuminate, 3-5-nerved; flowering glume shorter 

 than the outer glumes, smooth, shining, minutely striated; with 

 outer glumes removed, the spikelet resembles a small jassid. Barely 

 found in clovers. 



