94 THE AGRICULTURAL GRASSES OF THE UNITED STATES. 



pastures have been understocked, of going over them with a mowing 

 machine ; the orchard grass will then stool out, and the cattle will be 

 found eating first on the very spots that they had previously rejected. 

 (Plate 96.) 



POA. 



This is an extensive genus, there being about thirty-five species in 

 the United States, and it contains some of the most valuable grasses 

 for pasturage. 



The chief characters of the genus are as follows : Spikelets some- 

 what compressed, usually two to five flowered ; the axis between the 

 flowers glabrous, or sometimes hairy ; the flowers generally perfect, in 

 a few species dioecious ; the outer glumes commonly shorter than the 

 flowers, membranaceous, keeled, obtuse or acute, one to three nerved, 

 not awned 5 the flowering glumes membranaceous, five or rarely seven 

 nerved 5 the lateral nerves frequently very faint and obscure, often 

 scarious at the apex and margins ; the back, especially toward the 

 base, frequently pubescent on the nerves, often with a few or many 

 loose or webby hairs at the base ; palet about as long as its glume, 

 prominently two-nerved or two-keeled. 



PoA PRATENSis. (June grass, Kentucky blue grass. Spear grass.) 



This grass is too well known to need an extended description. It is 

 a perennial, growing usually IJ to 2 feet high, with an abundance of 

 long, soft, radical leaves. There are several well-marked varieties, 

 which are much modified and improved by good cultivation. It is 

 indigenous in the mountainous regions of this country as well as of 

 Europe, and has been introduced into cultivation in many countries. 

 The panicle is generally pyramidal in outline, 2 to 4 inches long, open 

 and spreading, the branches fine, mostly in fives, the lower ones 1 to 2 

 inches long, subdivided and flowering above the middle. The spike- 

 lets are about two lines long, ovate, closely three to five flowered, 

 mostly on very short pedicels. The outer glumes are acute ; the flow- 

 ering glumes acute or acutish, five-nerved, the lateral nerves prominent, 

 the lower part of the keel and marginal nerves more or less hairy, and 

 at the base more or less webby -hairy. From the unexampled success its 

 cultivation has met with in Kentucky it has acquired the name of 

 Kentucky blue grass, although in E'ew England it is known by the 

 name of June grass. In all the middle portions of the United States 

 it forms the principal constituent of pastures, though its excellence is 

 said to be rather depreciated in the Eastern States. 



In some sections it has been used as a hay grass, but it is not a success as a 

 meadow, its chief excellence being exhibited as a pasture grass. It endures the 

 frosts of winter better than any other grass we have, and if allowed to grow rank 

 during the fall months it will turn over and hide beneath its covering the most lux- 

 uriant of winter croppings. 



