4 BULLETIN 545, U. S, DEPARTMENT OF AGRICULTURE. 
The Arctic-alpine zone (alpine-meadow association), owing to its 
small carrying capacity and inaccessibility, has little or no value for 
grazing, and the character of its vegetation need not be discussed. 
On the Wallowa National Forest the vegetation which furnishes 
the greater part of the forage is distinctly herbaceous. It consists 
primarily of grasses, sedges, and rushes, with a fair representation 
of nongrasslike species commonly termed ''weeds." While the 
species are numerous, about 50 furnish virtually all of the range forage. 
GENERAL MORPHOLOGY OF GRASSES. 
In the discussion of the individual species it will be necessary to 
refer to specific characters in a general way as a means of distin- 
guishing one species from another. It is essential, therefore, that 
the reader have a clear conception of what a true grass is. The 
stems or culms are usually hollow except at the joints (nodes). 
The leaves consist of two parts, the sheath, which surrounds the culm 
usually like a split tube, and the blade. The minute flowers are 
arranged in spikelets consisting of a shortened axis (the rachilla) and 
from two to many 2-ranked scales, the lower two of which (the 
glumes) are empty, while each of the others (the lemmas) bears in 
its axil a flower inclosed in a 2-nerved scale (the palea). Lemma, 
palea, and flower, together, are termed the floret. The spikelets may 
be sessile (without a footstalk) along a jointed axis (the rachis), as 
in wheat and rye, the whole constituting a spike, or on little stems 
('pedicels) and arranged in panicles, as in mountain bunchgrasss and 
smooth bromegrass. The head of timothy is a panicle with the 
branches and pedicels greatly shortened. This is called a spikelike 
panicle. Sometimes the lemmas or the glumes bear bristlelike 
appendages termed awns. The "beard" of barley consists of awns. 
Plate II has been prepared to illustrate characters which will fre- 
quently be alluded to in the following discussion. In this illustration 
cultivated timothy (Phleum pra tense) and smooth bromegrass 
(Bromus inermis) are used because they are well known to stockmen 
and because they represent the morphology of two distinct and 
important tribes of grasses. 
IMPORTANT SPECIES. 
GRASSES. 
The grass family (Poaceae) contains about if, 500 known species. 
They vary in size from small, mosslike individuals in the extreme 
Polar regions to treelike growths of a hundred feet or more in the 
Tropics. As a whole, no family of plants enjoys a wider distribu- 
tion or grows in a greater variety of soils, and no other family 
is as important economically. From a grazing viewpoint the 
grasses are more valuable, all localities considered, than all other 
plants put together. 
The general taxonomio characters of grasses are shown in Plate II. 
