Question

Why do the leaves of touch me not droop down on touching?

Answer 1

When the compound leaf of sensitive plant ''touch me not'' is touched, it collapses and its leaflets fold together as it is undergone a shock. It results from a rapid loss of turgor by cells of the leaflets.

Answer 2

The touch-me-not plant's leaves droop when touched, as the water present in the leaves flows back into the plant in response to the stimulus.

EXPLANATION:

The touch-me-not plant (Mimosa pudica) is an interesting plant as it is one of the plants which can actively respond to a physical or environmental stimulus.

This plant keeps its leaves upright by maintaining the water content in the leaves (turgidity), when touched this water leaves the leaf to flow back into the plant body. This loss of water in the leaf causes them to droop.