The Dandelion in Colorado ii 
Beginning with the fourth day, following the first opening 
of the blossoms, a few of the heads were picked each day during 
the remaining six days, at the end of which time all that were left 
had come to maturity. After being allowed to dry, seeds were 
taken from each head and examined carefully or submitted to a 
germination test. 
RESULT OF GERMINATION TEST 
Number of days after beginning of bloom 
when heads were picked. 
4 
5 
6 
7 
8 
9 
Number of heads examined. 
3 
5 
5 
5 
6 
Highest percentage of germination from 
one head . 
0 
0.7 
0 
5.0 
16.6 
25.0 
Lowest percentage of germination from one 
head .. 
0 
0 
0 
0 
0 
8.3 
Average percentage of germination. 
0 
M 4 
^0 
"1.6 
10.0 
14.0 
From this experiment it appears that at least seven days must 
elapse, after the first opening of the flower heads, before any but a 
negligible number of seeds mature sufficiently to germinate. This 
fact has an important bearing upon the control of the dandelion in 
lawns for the rapid increase of the plant is due largely to the 
seeds which are allowed to mature upon the premises. Most of 
these seeds drop upon the ground near the parent plants, especially 
during the quiet days, and when the lawn is being watered by the 
hose they are washed down in contact with the soil where the 
conditions for germination are most favorable. If all blossom 
heads, including those that have closed to ripen the seeds, are 
picked or cut off once a week, the seed crop will be practically 
prevented even though the blossom heads are left on the lawn. 
NATURAL ENEMIES OF THE DANDELION 
The dandelion, like most weeds, has no serious natural en¬ 
emies capable of appreciably reducing its numbers or of holding 
it in check. Among insects are certain plant lice which some¬ 
times infest the plants and cause them to appear unhealthy or may 
occasionally be so abundant as to kill the plants outright. 
Fungous diseases of the dandelion, while not uncommon, sel¬ 
dom inflict serious damage to this host plant. One of the most 
common diseases of the dandelion is caused by a species of rust 
fungus (Puccinia Taraxaci ) which produces numerous minute pus¬ 
tules of a dark brown color on affected leaves. 
A species of mildew ( Sphaerotheca ) is also not uncommon 
upon the foliage of this plant, but the damage caused is slight. 
Another fungus ( Synchtyrium ) produces tiny swellings or galls 
upon the leaves of the dandelion which results in a partial stunt¬ 
ing of the foliage without killing it. 
