CHAP. I. 



TALL OAT GRASS. 



913 



that of the wavy hair grass (Aira flexuosa, L.), which somewhat 

 resembles it, has been known to be fraudulently substituted for it. 

 This hair grass is a product of poor heaths and sands, and is in- 

 capable of establishing itself in good meadows or pastures. 



TALL OAT GRASS, or false oat grass (Avena elatior, L., or Arrhena- 

 therum avenaceum, Beauv.), may frequently be found in or near the 

 hedgerows bordering grass-lands. Though often regarded as a weed, 

 yet, in its proper place, and in association with other grasses, there 

 is little doubt it possesses agricultural value. Foreign agriculturists 

 appreciate it more than do British farmers. It thrives best 



on 



Fig. 413. Tall Oat Grass. 



Avena elatior. 



Fig. 414. Downy Oat Grass. 



Avena pubescens. 



medium soils and clay loams, where, being a robust plant, it attains a 

 height of three or four feet. It can be found in ear from early summer 

 to late autumn, its spreading panicle (fig. 413) being made up of pale 

 or purplish spikelets, always of a shining appearance. The bitter 

 flavour of the plant is hardly noticeable when it is consumed in conjunc- 

 tion with other grasses. On arable soils there occurs a weed variety, 

 characterised by the formation of a bulb-like growth in the ground, 

 just above the root, to this form the name of " Onion couch " 

 is given. Avena elatior is known in the United States by such names 

 as Evergreen Grass, French Ryegrass, Grass of the Andes. 



Of the weed oat grasses, Avena pubescens is characterised (fig. 414) 

 by the dense covering of close-set hairs, which impart to the plant a 

 downy appearance. It may be found in dry pastures, especially in 

 chalk districts. It is readily distinguished from the valuable yellow 

 oat grass, thus : 



Spikelets. Liguje. 



Downy oat grass, Avena pubesceus . . Few, large . . Long, pointed. 

 Yellow oat grass, Avena flavescens . . . Many, small . . Short, blunt. 



3 N 



