108 Bulletin VII. 1. 



thinnest and apparently most sterile soils. There is, perhaps, no 

 better pasture grass than this for dry and poor soils. 



4. Poa pratensis Linn. Kentucky Blue-grass. 



Plate XXXVI. Figure 144. 



An erect perennial one to three feet high, with smooth stems, 

 flat leaves, open panicle and extensiv^ely creeping root-stocks. 

 Sheaths smooth; ligule about one-half aline long; leaf-blade flat, 

 four to ten inches long, one-half to three lines wide, apex abruptly 

 pointed. Panicle pyramidal, three to seven inches long, the pri- 

 mary branches usually in threes or fives. Spikelets about two 

 lines long, three- to five-flowered, mostly on very short, scabrous 

 pedicels; empty glumes a little unequal, the first narrowly-lanceo- 

 late and usually one-nerved, the second broader and three nerved, 

 flowering glumes ovate, scarious toward the apex, five-nerved, the 

 nerves silky-hairy below and with a small tuft of cobwebby hairs 

 at the base. 



This very well known native has been called the "King of pas- 

 ture grasses in the central basin of Tennessee," and whoever has 

 Blue-grass has the basis of all agricultural prosperity. It is not 

 so well adapted for hay as for pasture, but it makes an excellent 

 ''bottom grass" for the permanent meadow. Here it remains 

 green throughout the year, excepting in severe winter seasons, 

 and blooms in May. Poa pratensis is common to both Europe and 

 America, and grows "wild" in this country from Alaska southward 

 along the mountain ranges to Arizona, and east of the Mississippi it 

 extends southward to the Gulf States. It is only on good soils 

 that it yields well, doingbest on those which are highly calcareous. 



5. Poa trivialis L. Rough Meadow-grass. 



Plate XXXVII. Figure 145. 



An erect perennial, one to three feet high, with flat leaves, open 

 panicle and no conspicuous root-stock. Culm rough or scabrous 

 near the summit, not flattened. Sheaths a little scabrous; ligule 

 two to three lines long; leaf-blade three to six inches long, about 

 two lines wide, acute. Panicle narrowly-pyramidal, three to eight 

 inches long. Spikelets ovate, usually two-flowered. Empty glumes 

 strongly keeled, very acute, the lower one-nerved, the upper 

 broader and three-nerved; flowering glume ovate-lanceolate, 

 strongly five-nerved, fringed on the keel with silky hairs, other- 

 wise smooth. Palea smooth. 



This grass is closely related to the Kentucky Blue-grass, differ- 

 ing by the absence of any creeping root-stock, the rough stem, 

 longer ligule, more slender panicle, fewer-flowered spikelets, and 

 more prominently-nerved floral glumes. It has been cultivated 

 for many years in England, and is now highly esteemed both in 

 Britain and on the continent of Europe. Its principal use is to 

 form "bottom grass" in permanent meadows. It succeeds best 

 where the climate and soil are rather cool and moist. 



