246 BOTANY 
Pollination.—The dise flowers are protandrous. 
The pollen from the stamens is shed into the tube up 
which the style pushes its way. This style brushes 
out the pollen, and, when it emerges from the tube, 
splits, scattering the pollen on both sides and exposing 
the stigmatic surfaces on the inner side of the split. 
None of this pollen reaches these surfaces, and, as a 
rule, the flower is pollinated by pollen brought by 
insects from other flowers. If, however, eross- 
pollination does not take place, the two halves of the 
split style curl round and touch the pollen on the 
exterior surface of the style lower down, thus effecting 
self-pollination. 
The Dandelion (7araracwmn densleonis) (Fig. 139), 
is a typical member of the Liguliflore. 
The description of the dandelion flower answers 
that of the ray floret of the daisy with the following 
additions :— 
1. Calyx present as a pappus of hairs arising in five 
tufts. 
2. Andrecium—stamens five, syngenesious, epi- 
petalous. 
3. Distribution of fruit by wind with the help of a 
pappus of hairs derived from the five calyx lobes. 
In habit the dandelion is a perennial herb which 
exudes a milky fluid when eut or broken. The leaves 
form a rosette. 
The characteristics of the composite order are 
remarkably constant throughout a wide range of 
species. About 10 per cent of the plants of the globe 
belong to this order, which is generally considered as 
the head of the Vegetable Kingdom. As we have seen, 
it is specially adapted to survive in the struggle 
for existence in almost any surroundings. The massing 
of the flowers in heads, the epigynous condition, the 
reduction of the ovary to a one-celled bodv with a 
single ovule, the protandrous flower, with its simple 
