The whole leaf with its tendril, as well as the
young upper internodes, revolves vigorously and quickly, though
irregularly, and thus sweeps a wide space. The figure traced on a
bell-glass was either an irregular spire or a zigzag line. The
nearest approach to an ellipse was an elongated figure of 8, with one
end a little open, and this was completed in 1 hr. 53 m. During a
period of 6 hrs. 17 m. another shoot made a complex figure,
apparently representing three and a half ellipses. When the lower
part of the petiole bearing the leaflets was securely fastened, the
tendril itself described similar but much smaller figures.
This species climbs well. The tendrils after clasping a stick become
thicker and more rigid; but the blunt hooks do not turn and adapt
themselves to the supporting surface, as is done in so perfect a
manner by some Bignoniaceae and Cobaea. The tendrils of young
plants, two or three feet in height, are only half the length of
those borne by the same plant when grown taller, and they do not
contract spirally after clasping a support, but only become slightly
flexuous. Full-sized tendrils, on the other hand, contract spirally,
with the exception of the thick basal portion.
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