Nastic
Nastic movements are plant movements that occur in response to external stimuli but are non-directional with respect to the stimulus. Unlike tropisms, which involve directional growth toward or away from a stimulus, nastic responses are not oriented toward the source of stimulation. They are often rapid or reversible and are typically driven by changes in turgor pressure within specialized cells, such as those in the pulvinus at the base of leaves or leaflets.
Nastic movements are categorized by the type of stimulus involved. Nyctinasty refers to daily or circadian
These movements are typically driven by rapid ion fluxes and water shifts across cell membranes, causing reversible