noun
- a swollen joint or node at the base of a leaf or leaflet that controls movement in plants
Usage: botanical
Examples
- The pulvinus at the base of the mimosa leaf causes it to fold when touched.
- Plant biologists study the pulvinus to understand how leaves track sunlight.
- The sensitive plant’s rapid leaf movement is controlled by its pulvinus.
- Water pressure changes in the pulvinus enable the prayer plant’s daily movements.
- Each leaflet has its own pulvinus that responds to environmental stimuli.