240 PRACTICAL COURSE IN BOTANY 
as it must now depend upon the conveyance of pollen to the 
stigma by extraneous means. 
274. Adaptations to wind pollination.— A very large 
number of plants, among which are included nearly all our 
principal forest trees, grains, 
and grasses of every kind, 
depend exclusively upon the 
wind for the distribution of 
their pollen. This being 
the case, it is, of course, an 
advantage to them to get 
rid of all unnecessary ap- 
pendages that might hinder 
a free play of the wind 
among their flowers, and so 
they consist, as a rule, of 
essential organs only (Figs. 
341, 342). Such flowers are 
often distinguished, how- 
i ever, especially among 
ee grass. grasses and low herbs, by 
large, feathery stigmas that 
are well adapted to catch and hold any stray pollen grains 
which may be floating in the air. Place a stigma of oat or 
other grass under the microscope and you will probably see 
a number of pollen grains clinging to its branches. 
275. The disadvantages of wind pollination. — This is a 
very clumsy and wasteful method, however, for so much 
pollen is lost by the haphazard mode of distribution that the 
plant is forced to spend its energies in producing a vast 
amount more than is actually needed, and great masses of it 
are frequently seen in spring floating like patches of sulphur 
on ponds and streams in the neighborhood of pine thickets. 
Like those that are self-pollinated, wind-pollinated flowers 
are generally very inconspicuous, devoid of odor, and of all 
attractions of form or color, because they have no need of 
