flaccidity

A turgid plant cell (left) and a flaccid plant cell. Water leaves and enters the cell by osmosis. If too much water leaves the cell, for example during drought or saline conditions, then turgor is lost and the cell becomes flaccid. As turgor gives the plant rigidity, loss of turgidity results in the plant wilting.

In botany, the loss of rigidity (turgor) in plant cells, caused by loss of water from the central vacuole so that the cytoplasm no longer pushes against the cellulose cell wall. If this condition occurs throughout the plant then wilting is seen.

Flaccidity can be induced in the laboratory by immersing the plant cell in a strong saline solution. Water leaves the cell by osmosis causing the vacuole to shrink. In extreme cases the actual cytoplasm pulls away from the cell wall, a phenomenon known as plasmolysis.