Like most inverted blossoms, the harebell hangs its head to
protect its nectar and pollen, not only from rain, but from the
intrusion of undesirable crawling insects which would simply
brush off its pollen in the grass before reaching the pistil of
another flower, and so defeat cross-fertilization, the end and
aim of so many blossoms. Advertising for winged insects by its
bright color, the harebell attracts bees, butterflies, and many
others. These visitors cannot well walk on the upright petals,
and sooner or later must clasp the pistil if they would secure
the nectar secreted at the base. In doing so, they will dust
themselves and the immature pistil with the pollen from the
surrounding anthers; but a newly opened flower is incapable of
fertilization. The pollen, although partially discharged in the
unopened bud, is prevented from falling out by a coat of hairs on
the upper part of the style. By the time all the pollen has been
removed by visitors, however, and the stamens which matured early
have withered, the pistil has grown longer, until it looks like
the clapper in a bell; the stigma at its top has separated into
three horizontal lobes which, being sticky on the under side, a
pollen-laden insect on entering the bell must certainly brush
against them and render them fertile.
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