Pulvinus

pulvini) may refer to a joint-like thickening at the base of a plant leaf or leaflet that facilitates growth-independent movement.

[citation needed] Pulvinar movement is caused by changes in turgor pressure leading to a contraction or expansion of the parenchyma tissue.

The increased sugar concentration in the apoplast decreases the water potential and triggers the efflux of potassium ions from the surrounding cells.

Touch response (thigmonastic) movements appear to be regulated through electrical and chemical signal transduction spreading the stimulus throughout the plant.

[6] Water flux out of the cell's symplast and into its surrounding apoplast results in a decrease in turgor pressure, and the characteristic closing of the leaves of Mimosa pudica.