- Botany. a cushionlike swelling at the base of a leaf or leaflet, at the point of junction with the axis.
- Architecture. pulvinar(def 2).
Origin of pulvinus
First recorded in 1855–60, pulvinus is from the Latin word pulvīnus cushion
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for pulvinus
Tropic response of pulvinus of Desmodium gyrans: Experiment 131.Life Movements in Plants, Volume II, 1919
Sir Jagadis Chunder Bose
In Mimosa, the responsive movement is brought about by a sudden diminution of turgor in the pulvinus.
This is accentuated by the expansion of the upper half of the pulvinus which is normally in a state of compression.
In Mimosa excitation is manifested by the contraction of the pulvinus and the consequent movement of the leaf.
The moto-excitability of the pulvinus of Mimosa is greatly modified under the influence of temperature.
- a swelling at the base of a leafstalk: changes in its turgor pressure cause changes in the position of the leaf
C19: from Latin: cushion