perennis of Gray). The
latter has loose racemes of smaller purple flowers and leaflets
in threes; nevertheless it is often confounded with the
ground-nut vine by older naturalists whose knowledge was "learned
of schools."
Usually a bee, simply by alighting on the wings of a blossom
belonging to the pea family, releases the stamens and pistil from
the keel; not so here. The sickle-shaped keel of the ground-nut's
flower rests its tip firmly in a notch of the standard petal, nor
will any jar or pressure from outside release it. A bee, guided
to the nectary by the darker color of the underside of the curved
keel which spans the open cavity of the flower, enters, at least
partially, and so releases by his pressure, applied from
underneath, the tip of the sickle from its notch in the standard.
Now the released keel curves all the more, and splits open to
release the stigmatic tip of the style that touches any pollen
the bee may have brought from another blossom. Continuing to
curve and coil while the bee sucks, it presently dusts him afresh
with pollen from the now released anthers.
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