MANUAL OF THE GRASSES OF THE UNITED STATES 



331 



10. Agrostis alba L. 



Redtop. (Fig. 665.) 

 Differing from A. 

 stolonifera in its usually 

 erect more robust 

 culms, sometimes as 

 much as 1 to 1.5 m 

 tall, the base erect or 

 decumbent, with 

 strong creeping rhi- 

 zomes; blades flat, 5 

 to 10 mm wide; pan- 

 icle pyramidal-oblong, 

 reddish, as much as 20 

 cm long, the branches 

 spreading in anthesis, 

 sometimes contracting 

 later; lemmas rarely 

 awned. % — This is 

 the common redtop 

 cultivated for mead- 

 ows, pastures, and 

 lawns, extensively 

 escaped in all the 

 cooler parts of the 

 United States; Eur- 

 asia. This form ap- 

 pears not to be native 

 in America. Plants 

 growing without cul- 

 tivation may tend to 

 take on the aspect of 

 A . stolonifera . This 

 and the two preceding 

 are closely allied and 

 appear to intergrade. 

 The name A. palustris 

 has been erroneously 

 applied to this species 

 in recent works. 



Figure 685.— Agrostis alba. Plant, X Yi, 2 spikelets and floret, X 5. (Chase 5191, Mont.) 



