The young internodes, on the other hand,
revolve in ellipses, and carry with them the tendrils. Two ellipses
were completed, each in nearly 5 hrs.; their longer axes were
directed at about an angle of 45 degrees to the axis of the
previously made ellipse.
Lathyrus grandiflorus.--The plants observed were young and not
growing vigorously, yet sufficiently so, I think, for my observations
to be trusted. If so, we have the rare case of neither internodes
nor tendrils revolving. The tendrils of vigorous plants are above 4
inches in length, and are often twice divided into three branches;
the tips are curved and are sensitive on their concave sides; the
lower part of the central stem is hardly at all sensitive. Hence
this plant appears to climb simply by its tendrils being brought,
through the growth of the stem, or more efficiently by the wind, into
contact with surrounding objects, which they then clasp. I may add
that the tendrils, or the internodes, or both, of Vicia sativa
revolve.
COMPOSITAE.--Mutisia clematis.--The immense family of the Compositae
is well known to include very few climbing plants. We have seen in
the Table in the first chapter that Mikania scandens is a regular
twiner, and F.
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