26 BULLETIN .545, U. S. DEPARTMENT OF AGRICULTURE. 
Since tall meadow-grass is entirely restricted to wet soils, the root 
system is not extensively developed, and it requires a relatively high 
amount of moisture to supply its needs. In its typical habitat it 
wilted beyond recovery when the soil water was reduced to from 
12 to 14.5 per cent. 
The average period of flower-stalk production extends over about 
three weeks, beginning about July 10, while by August 1 most of the 
stalks have been sent forth. The seed begins to ripen about Au- 
gust 20, and by September 10 the crop is practically all matured 
and disseminated. Seeds are dropped immediately upon ripening. 
The germinative power of the seed crop, as tested in 1908, gave 
an average of 85 per cent, and since reproduction of this species seems 
to be generally good, it is probable that the seed has a high average 
vitality. 
Tall meadow-grass (Plate XX), like a number of other species 
with a high-water requirement, supplies only a hmited amount of 
forage. It is relished by all classes of stock, and is probably most 
valuable as forage during August, since it is then less succulent than 
earlier in the season. Up to August 1 the flower stalks are eaten 
nearly to the same extent as the leaf buds, but after that period they 
become somewhat tough and are not usually eaten by sheep. Horses 
and cattle, however, continue to consume the entire plant until much 
later in the season. 
Another species, P. paucifiora, very commonly associated with 
tall meadow-grass, has similar distribution and habits. P. pauciflora, 
however, does not occur as abundantly and, consequently, is not as 
valuable as a forage plant. It is readily distinguished by having o 
nerves on the lemma instead of 7, as in the case of tall meadow grass. 
Big Bunch Grass. 
(Agropyron spicatum.) 
The grass tribe, Hordeae, to which this and the following five 
species belong, is of high importance in the West. The genus 
Agropyron contains about 40 species, more than half of which are 
found in the United States. Of these, many are highly valuable 
for hay and forage. 
Big bunch grass or blue bunch grass, as it is sometimes called 
because of the characteristic blue-colored culms or stems, is a peren- 
nial with deep fibrous roots. The culms, smooth and covered with 
"bloom," attain a height of about 12 to 18 inches in dry situations 
where this grass characteristically occurs, while in deep rich soils of 
abundant moisture a height growth of about 30 inches is sometimes 
made. The leaf blades, about half the length of the culm, are mainly 
basal and produced in abundance. They are flat when green, but 
slightly rolled inwardly when the plant is air dry or suffering for lack 
