6 The Colorado Experiment Station 
are crowded by other taller vegetation, they stand in more or less 
erect tufts. This difference in habit of growth also corresponds 
in a large degree to the age of the plant. Thus during the first 
year from seed the rosette habit is characteristic, while in old 
plants which have a branched root crown the leaves are forced into 
erect clumps by mutual crowding. The leaves of plants growing 
Fig. 3. One-inch lengths of a dandelion root sprouting after being in 
moist sand for 18 days. The smallest piece was 18 inches below the surface 
of the ground when the plant was dug up. 
in shady places are thinner and more tender than those in full 
sunlight. 
The surface of the dandelion leaf is covered with a thin epi¬ 
dermis which is readily wet by water and other liquids. This is 
one of the vulnerable points in the dandelion plant, as it makes 
possible the use of certain spray mixtures which readily destroy 
its foliage, while other plants, like the grasses, may escape with 
but little injury. 
