228 A TEXT-BOOK OF GRASSES 
most important genera of forage grasses. The species are 
ab: ndant in the grazing areas of our western mountains 
an several species are cultivated. 
‘252. Kentucky blue-grass——Culms from a few inches 
to 2 feet or more in height from slender creeping rhizomes; 
sheaths smooth; ligule short; blades flat or somewhat 
folded, ending like most species of the genus, in a boat- 
shaped blunt point, panicle 2 to 4 inches long or sometimes 
larger, pyramidal, open, the lower branches in groups of 
about 5; spikelets 3- to 5-flowered, 4 to 5 mm. long; lemmas 
pubescent on the keel and marginal nerves, bearing a 
tuft of cobwebby hairs at base. Commonly cultivated as 
a lawn- and pasture-grass. 
Poa pratensis L. (Fig. 54.) Kentucky blue-grass. Perennial, in 
tufts but producing slender creeping rootstocks; culms slender, 
erect, smooth, terete or slightly flattened, 1 to 3 feet high; sheaths 
smooth, sometimes slightly keeled; ligule membranaceous, short, 
truncate, about 1 mm. long; blades, especially the basal, long and 
narrow, flat or usually partly folded or conduplicate, usually not 
over 4 mm. wide, the uppermost 1 to 3 inches long, appressed, 
slightly roughened on the margins and keel, especially toward the 
boat-shaped tip; panicle open, pyramidal or oblong, 3 to 6 inches 
long, the scabrous branches naked below, the lower in whorls of 
usually 5, one being stronger; spikelets ovate or lanceolate, flat- 
tened, 4 to 6 mm. long, usually 3- to 5-flowered, the ultimate pedi- 
cels about 1 mm. long; glumes narrow, acute, the first 1-nerved, 
the second 3-nerved; lemma 5-nerved, acute, hyaline or papery and 
often purple-tinged at apex, about 4 mm. long, the keel and margi- 
nal nerves pubescent, the base bearing a tuft of cobwebby hairs. 
The boat-shaped apex of the blades is characteristic of the genus. 
Blue-grass is a native of Europe and may also be native in the 
northern parts of North America. In open dry or sterile soil the 
flowering culm may be only a few inches in height. In color the 
foliage is a dark green and does not have a blue color as the name 
would indicate. As it flowers in June, the name June-grass is 
applied to this species in parts of the northern United States. 
