Member-only story
Now you see it
…now you don’t
There is a small patch of Sensitive Plant (Mimosa pudica, Fabaceae) in the garden. Native to Central and South America, this species has been introduced elsewhere and is now widespread in Africa, Asia and Australia. It is sometimes grown as a pot plant — but not for its delicate fern-like foliage or its fluffy pink flowers. It is grown for its unusual behaviour.
In 1797, physician Robert Hooper wrote of the plant
The MIMOSA PUDICA or bashful sensitive plant. By the least touch the leaves instantaneously recede, contract, close and, together with the footstalk, quickly decline downwards, as if ashamed of the approach of the hand.
This reaction to contact was known as a curiosity in several species of Mimosa. On the Lively Mimosa (M. viva) of Cuba and Jamaica, which sprawls over large areas, Hooper said
by running a stick over a plant a person may write his name; and it will remain visible for ten minutes.
Living graffiti! I have a stick. Now I all I need to do is find a plant.
The movement is caused by changes in pressure inside structures called pulvini (singl. pulvinus). Pulvini are distributed along the stem and at the base of every leaflet. When something touches the plant, water is shunted out of the cells of the pulvini, causing the…
