42 
THE AMERICAN BOTANIST. 
Years ago the willows were also fertilized by the w^ind, 
but to-day the\' depend upon inseets to carr^^ their pollen. 
These trees all blossom before or with the appearance of 
their leaves, and many people never know that they bloom 
at all. It is not difficult to understand why they flower 
so early, for the leaves later in the season would intercept 
the flight of the pollen. 
Wind-pollinated plants have small and inconspicuous 
flowers which are green or dull-colored. Usually they 
flower and fruit entirely unnoticed. It would be of no 
advantage for them to produce bright colors or sweet 
odors, for the w^ind bloweth where it listeth regardless of 
all such attractions. The birches, however, have golden 
and greenish 3^ellow aments and the blossoms of the elm 
are purplish. The glumes of grasses and the perianth of 
rushes are also often purplish or reddish. So conspicuous 
are the flowers of some rushes in Europe that they even 
attract a few insects. The sorrels sometimes have the 
entire plant red-colored, and in the Alps Muller saw a 
butterfly examining a plant for honey. The plantains are 
midway between wind-fertilization and insect-fertiliza- 
tion. Some odoriferous species display several hues and 
attract not a few inseets. But as a whole wind-pollin- 
ated plants have small greenish flowers. 
Setting aside the great company of dull-colored wind 
flowers there remain in northeastern America 2,972 
Species, w^hich are pollinated by insects or are self-pollin- 
ated. Of this number 223 have green, 955 white, 790 
yellow, 257 red, 422 purple and 325 l)lue flowers. Most of 
these 223 green flowers are small or even minute, and many 
of them have no petals. They are attractive chiefly to flies 
and the smaller bees, as in the smilax and sumac families. 
But the green pendulous flowers of the garden asparagus 
are favorites of the hone3^bee. In the grape family the 
petals never expand, but fall awaj^ by separating at the 
base and coiling spirally upw^ard. The fragrance which 
resembles that of mignonette can be perceived at a long 
distance. Kerner relates that in a journey up the Danube 
