32 BULLETIN 1450, U. S. DEPARTMENT OF AGRICULTURE 
crude fiber and more material classed as nitrogen-free extract than 
did the parts of the shoots, including the leaves, which are above 
the haplocorm (S3, p. lfi-50). Although the haplocorm is not essen- 
tial to vegetative reproduction of timothy, it may possibly serve to 
some extent as a storage of nutrients which are used by those innova- 
tions which grow from the buds at the base of elongated shoots 
during the summer months. It is also possible that some of the 
material stored in the haplocorm later becomes transferred to the 
seeds, which mature about 8 or 10 weeks after the haplocorm has 
completed its growth. 
LEAVES 
The leaves of timothy are composed of two main parts, the sheath 
and the linear blade, at the juncture of which there is a relatively 
short, broad, glabrous ligule. The size of timothy leaves in a general 
way corresponds to the size of the plant on which they grow. The 
leaves of a vigorous plant several months old are larger in both 
length and width than those of a plant only a few weeks old. 
THE PROPHYLLUM 
On innovations the first leaflike organ is short, with no blade; 
this is the prophyllum (13, p. 5-0). It grows with its back to the 
axis of the primary shoot, in the same plane as the leaves of the 
primary shoot, and in a plane at right angles to the plane in which 
the other leaves of the innovation grow. 
THE LEAF SHEATHS AND BLADES 
The first leaf above the prophyllum generally has a short, rudi- 
mentary blade, not exceeding 0.25 inch in length, though frequently 
no blade at all is developed. The second leaf above the prophyllum 
usually has a normal blade, though it also is sometimes short and 
rudimentary. 
The sheaths of the leaves on a timothy shoot on which none of the 
internodes have become elongated are relatively short. The sheath 
of each leaf is inclosed within the sheath of the next older leaf. Dur- 
ing the fall, winter, and early spring, up to the time when the upper 
internodes become elongated to form a culm, the growing bud of the 
shoot is inclosed within and near the base of the sheaths of all leaves 
which have developed on it (17, p. 99). 
The sheath of each leaf is usually slightly longer than the sheath 
of the next older leaf. Thus, on five typical shoots which were col- 
lected from a timothy meadow October 29, 1917, the average length 
of the sheath of the first leaf above the prophyllum was 0.68 inch; 
of the second leaf, 0.95 inch ; and of the third leaf, 0.99 inch. ^ The 
sheaths of the leaves which develop in the spring, before the inter- 
nodes begin to become elongated, have sometimes been found to 
grow to a length of 3 inches or more. 
Like the corresponding internodes of the culm, the leaf sheaths 
are progressively longer toward the upper part of it. The lower 
internodes in the elongated part of the shoot are frequently entirely 
inclosed within the leaf sheaths. In the upper part of the culm the 
sheaths of the leaves are shorter than the corresponding internodes, 
