Mimosa pudica

Abstract

A plant, Mimosa pudica L. (Ojigi-so in Japanese), is known by the very rapid movement of the leaves when it is stimulated by touch, heating, etc. However, it is well known that there is another movement of the leaves in M. pudica, that is a very slow, periodical movement of the leaves called nyctinastic movement which is controlled by a biological clock. We have isolated the chemical substance inducing the slow movement of the leaf of M. pudica. This chemical substance induced only the slow movement of the leaf and could not induce the rapid movement. The slow and rapid movements of mimosa would be regulated by different chemical substances.