--This well-named, elegant, annual species
differs from the other members of the group observed by me, in the
young internodes having the power of revolving. It exceeds all the
other climbing plants which I have examined, in the rapidity of its
movements, and all tendril-bearers in the sensitiveness of the
tendrils. The internode which carries the upper active tendril and
which likewise carries one or two younger immature internodes, made
three revolutions, following the sun, at an average rate of 1 hr. 4
m.; it then made, the day becoming very hot, three other revolutions
at an average rate of between 57 and 58 m.; so that the average of
all six revolutions was 1 hr. 1 m. The apex of the tendril describes
elongated ellipses, sometimes narrow and sometimes broad, with their
longer axes inclined in slightly different directions. The plant can
ascend a thin upright stick by the aid of its tendrils; but the stem
is too stiff for it to twine spirally round it, even when not
interfered with by the tendrils, these having been successively
pinched off at an early age.
When the stem is secured, the tendrils are seen to revolve in nearly
the same manner and at the same rate as the internodes.
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