In Tr. subterraneum
the main peduncle curves downwards for the sake of burying its capsules,
and in this species the sub-peduncles of the separate flowers bend
* 'Ueber Orthotrope und Plagiotrope Pflanzentheile;' 'Arbeiten des Bot.
Inst., in W?rzburg,' Heft ii. 1879, p. 226.
[page 277]
Fig. 124. Trifolium repens: circumnutating and epinastic movements of the
sub-peduncle of a single flower, traced on a vertical glass under a
skylight, in A from 11.30 A.M. Aug. 27th to 7 A.M. 30th; in B from 7 A.M.
Aug. 30th to a little after 6 P.M. Sept. 8th.
[page 278]
upwards, so as to occupy the same position relatively to the upper part of
the main peduncle as in Tr. repens. This fact alone would render it
probable that the movements of the sub-peduncles in Tr. repens were
independent of geotropism. Nevertheless, to make sure, some flower-heads
were tied to little sticks upside down and others in a horizontal position;
their sub-peduncles, however, all quickly curved upwards through the action
of heliotropism. We therefore protected some flower-heads, similarly
secured to sticks, from the light, and although some of them rotted, many
of their sub-peduncles turned very slowly from their reversed or from their
horizontal positions, so as to stand in the normal manner parallel to the
upper part of the main peduncle.
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