G95 

 BLUEGRASSES 



Po'a spp. 



The bluegrasses compose one of the largest, most important eco- 

 nomically, and most taxonomically difficult genera of the grass family 

 (Gramineae). Under the type basis of botanical nomenclature it 

 becomes the type of the grass family to which it gives the name 

 Poaceae, used in many of the botanical manuals. The bluegrasses 

 belong to the immense fescue tribe (Festuceae), which includes the 

 broinegrasses, fescues, melic grasses, orchard grass, and numerous 

 other well-known genera. The name poo, is a Greek word for grass, 

 or .any plant used as fodder by domestic livestock. The common name 

 bluegrass refers to the characteristic blue-green color of the foliage 

 of many species of Poa and perhaps Avas first applied to the species 

 now called Canada bluegrass (P. compressa) . The bluegrasses are 

 often called speargrasses, and sometimes also pinegrasses and green- 

 grasses. In England they are called meadowgrasses, because they 

 are important constituents of most meadow pastures. 



The bluegrass genus is easily the largest and one of the most widely 

 distributed groups of western range grasses. On a conservative basis 

 about C5 species of Poa occur on western range lands, and between 

 about 150 and 200 species grow throughout the world, particularly 

 in the temperate and cooler regions. Save only in the hotter and 

 drier climates, almost wherever grasses grow, from the seashore to 

 the highest limit of vegetation on the loftiest peaks, from the Arctic 

 to the Antarctic, the genus Poa, is represented. 1 



Bluegrasses are widely distributed throughout the United States, 

 the majority occurring in the mountainous regions of the northern 

 and western sections of the country. All but three or four of them 

 are perennials. Bluegrasses are relatively unimportant in the South- 

 west, because the climate is too dry and the winds too desiccating, 

 except in the higher mountains, to permit them to grow successfully. 



While most of the species occurring in the United States are 

 native, a few have been introduced and cultivated for pasturage and 

 lawns, thus greatly extending their range. Especially prominent 

 among these foreign species are Kentucky bluegrass (P. pratensis) 

 and Canada bluegrass, which have been planted extensively in 

 Canada and the northern half of the United States as far west as 

 Missouri and Iowa and, to a more limited extent, in the mountainous 

 regions of the South and West. These two cultivated species have 

 spread aggressively and are now common along ditch banks, in 

 meadows, along roadsides, and are even moderately abundant on 

 some of the western ranges. Native species of bluegrass are often 

 the most important forage grasses of many of the cooler and moister 

 western ranges. They occur in a great variety of sites, from sand 

 dunes to mountain meadows. The majority, however, favor rich, 

 moist, well-drained soils and are characteristic of meadows, grassy 

 parks along stream banks, in shaded woodlands, and in open sage- 



1 Lamson-Scribner, F. ECONOMIC GRASSES. TJ. S. Dept. Agr., Div. Agrost. Bull. 14, rev., 

 85 pp., illus. 1900. 



