6 
SOME COLORADO GRASSES. 
above the joint. The flowers of sedges are in a solid 
spike, while in grasses they are displayed in spike racemes 
or panicles. 
Grasses are classified as follows : 
I. The cereal grasses, comprising wheat, oats, barley, 
corn and rice. 
II. . Hay and pasture grasses, including the well- 
known orchard grass and timothy. 
III. Cane grasses, as sorghum, sugar cane, etc. 
IV. Ornamental grasses, such as the pampas grass. 
V. Weedy grasses, represented in burr grass, 
(Cenchrus tribuloides), pigeon grass, chess, etc. 
The number of known species is about thirty-five 
hundred, widely distributed the world over, being 
especially predominant in temperate regions, where they 
carpet the surface of the earth with a soft green turf, but 
in tropical countries, their habit disappears, the grasses * 
growing in isolated tufts, having broader leaves and more 
showy flowers. 
All the grasses contain, in a greater or less degree, 
especially before blooming, a sugary mucilage. The 
creeping root stocks, too, are generally demulcent and 
mucilaginous, besides being invaluable in securing the 
stability and permanancy of shifting sands. 
And every tiller of the soil recognizes their import¬ 
ance in the production of hay and pasturage. In the 
United States, we have a great variety of conditions, of 
both soil and climate, with which to contend, and the 
number of species of grass in cultivation is less than a dozen. 
The following characteristics of grasses are explained 
here, that observing persons may be the better prepared 
to recognize the leading species without great difficulty : 
The root consists of many strong fibres branching 
through the soil in various directions, often binding it 
