Definition of pulvinus in US English:


nounPlural pulvini

  • An enlarged section at the base of a leaf stalk in some plants that is subject to changes of turgor, leading to movements of the leaf or leaflet.

    • ‘The ion flux occurs within seconds after gravistimulation and establishes pH gradients across roots and maize pulvini.’
    • ‘With the exception of petiole length, pulvinus length and stipule length, the other leaf characteristics overlap between the two species.’
    • ‘When the promoter fragment was resolved into smaller portions, further elements could be identified that conferred root, pulvinus and anther expression.’
    • ‘Soluble proteins were extracted from gravistimulated pulvini and subjected to protein phosphorylation reactions.’
    • ‘Leaves move by means of turgor pressure changes at the pulvinus at the base of each lamina.’


Mid 19th century: from Latin, literally ‘cushion’.