vas at vas.dcs.aber.ac.uk
Mon Feb 21 17:31:06 EST 1994
In article <2kdii3$9g5 at mserv1.dl.ac.uk> ajt at rri.sari.ac.uk (Tony Travis) writes:
>: >Any roadside in India and the Himalaya will yield M. pudica bushes
>: >in prickly abundance. A glance shows why it does what it does: as
>: >a feathery light green bush, it is irresistable to cattle. At the
>: >first nibble, however, the entire thing collapses into a boring
>: >bundle of twigs and the cow browses off.
>: This is the only explanation I've heard for the Mimosa "behaviour". It would
>: suggest that the herbivore(s) under which the closing adaptation evolved (not
>: necessarily cows?) browse on the basis of visual stimuli, rather than, say,
>: how the plant feels to the mouth. Is there any evidence for this? Does
>: anybody have an alternative explanation for the Mimosa adaptation?
>: Frank van de Loo.
>It is also likely to be a defence mechanism against damage to the
>foliage during torrential rain. The laminae of leaves subjected to
>this type of mechanical stress can adapt in two ways: one is to be
>strong enough not to be damaged (Ficus), the other is to minimise the
>area of the leaf and drop the petioles to reduce the angle of impact of
>raindrops. The 'sensitivity' of Mimosa pudica is such that it would
>effectively change habit when the first few drops of heavy rain hit it.
I'd heard that is was more to put off flying insects. If an insect
lands on the plant with the intention of eating it (or any other
intention come to that) and the plant/platform dissapears from under
it the insect is likely to fly off and leave the plant intect.
More information about the Plantbio