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[Plant-education] How Does Epinasty (the Epinastic Affect) Help a Plant During Flooding?

socrtwo at gmail.com socrtwo at gmail.com
Tue Jun 28 21:36:50 EST 2005

Suggestion: Epinasty during flooding is adaptive because the downward
directed leaves act as sails in the wind, and the wind action on the
leaf acts on the plant and leaf stems like somebody working a lever
water pump.

That is there is a physical mechanism within the stem similar to a
lever water pump which is activated by the up and down movements of
Epinastic leaves blown in the wind. There therefore should be
structures in the stem analogous to the piston, valves etc.

The idea is that a flooded plant needs to pump water out of space
surrounding the roots as quickly as possible.  Epinasty then does this
through ramped up transpiration induced by a higher water pressure from

a lever pump action.  (Maybe downward directed leaves also transpire
more quickly in the wind even without pump action because when they
become perpendicular to it -to the wind- or when the plant makes sure
epinastically grow perpendicular to the most common prevailing wind -
this makes transpiration faster than if the leaves are parallel to the
wind as the are on the most part during normal conditions.)

Teachers might have students dissect plants looking for the possible
mechanism, which they could display in science projects.

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