Leaves droop when touched

MIMOSA Pudica is a straggling weed which can be found locally in the Hongkong countryside, especially on recently reclaimed wasteland.

The plant grows to 45 cm in height. Its spherical pink flowers can be easily be seen during late summer.

When you touch it, the leaves will close and droop. Electrical signals, which are started by touch, pass information along the plant's body.

When a signal reaches the cells of the stalks, it causes a loss of water in the cells. This loss of water causes reduction in pressure which results in the branches wilting.

About 20 minutes after wilting, the leaflets open out again and the stalks resume their normal positions.

We do not know for certain but sensitivity probably discourages animals from eating the plant.