24 BULLETIN 1450, U. S. DEPARTMENT OF AGRICULTURE 
DESCRIPTION OF STERILE SHOOTS 
The differences between timothy shoots which produce an inflores- 
cence and those which are sterile have already been outlined. In 
the following paragraphs the more important of these differences 
are discussed more fully. Typical sterile shoots as they appear in 
midsummer are shown at the left in Plate 4, B. 
STEKILE SHOOTS ARE RELATIVELY SHORT 
One of the most conspicuous of the distinctions between fertile 
and sterile shoots is that those of the latter type are shorter and 
also more slender than fertile shoots. In one meadow in which 
the average fertile shoot growing in a typical area measured 38.1 
inches in length, it was found that the lengths of the sterile shoots 
growing in the same area varied from 7.5 to 22.5 inches and their 
average length was 14.4 inches. 
STERILE SHOOTS HAVE RELATIVELY LARGE NUMBERS OF ELONGATED INTERNODES 
Another one of the characteristics which distinguish sterile tim- 
othy shoots is the greater number of elongated internodes and leaves 
than on fertile shoots. 
On July 20, 1912, and again on July 20, 1916, 10 typical shoots 
of each type were selected from a meadow and a count was made of 
the internodes and leaves on the elongated part of each. On July 
20, 1912, on the fertile shoots there was an average number of 6.4 
elongated internodes and on the sterile shoots 8.4 elongated inter- 
nodes; on July 20, 1916, there was an average number of 6.9 elon- 
gated internodes on the fertile shoots and 8.5 elongated internodes 
on the sterile shoots. 
As the season progresses the number of leaves on sterile shoots 
continues to increase as long as they remain green and continue 
growth. On 10 shoots of this type which were collected on December 
12, 1918, the average number of leaves which had developed from 
the leaf below the haplocorm to the one at the tip of each stem 
was 17.3. 
GROWTH OF STERILE SHOOTS MAY CONTINUE INDEFINITELY 
Though the growth of new leaves from a fertile shoot ceases when 
the inflorescence develops, leaves continue to form on sterile timothy 
shoots until growth is checked by cold weather in late fall or early 
winter, unless the shoots dry up or are destroyed in some other way 
during late summer or early fall. This habit of growth is one of 
the most prominent of the characteristics of sterile shoots. 
That the growth of a sterile shoot may continue through more 
than one season is shown by the results of two experiments described 
below. 
A timothy plant having a sterile shoot was taken from the field 
late in November and transferred to a greenhouse December 18, 1918. 
The shoot was bent over and the tip partly covered with soil. On 
January 7, 1919, it was found that roots had developed from the 
covered nodes at the tip of the shoot and the new leaves were making 
a vigorous growth. The elongated internodes which developed in 
