pulvinus

American  

[puhl-vahy-nuhs] / pʌlˈvaɪ nəs /

noun

plural

pulvini

1. Botany. a cushionlike swelling at the base of a leaf or leaflet, at the point of junction with the axis.

2. Architecture. pulvinar.

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pulvinus British  

/ pʌlˈvaɪnəs /

noun

1. a swelling at the base of a leafstalk: changes in its turgor pressure cause changes in the position of the leaf

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Etymology

Origin of pulvinus

First recorded in 1855–60, pulvinus is from the Latin word pulvīnus cushion

Example Sentences

In these seedlings there could hardly be a doubt that the pulvinus was becoming rudimentary and tending to disappear; and this accounts for its great variability in structure and function.

From The Power of Movement in Plants by Darwin, Charles

The movements of pulvinated cotyledons are generally larger in extent than those without a pulvinus; nevertheless some of the latter moved through an angle of 90o.

From The Power of Movement in Plants by Darwin, Charles

These leaves, which moved so little, had a fairly well-developed pulvinus.

From The Power of Movement in Plants by Darwin, Charles

The sinking movement is due to the downward curvature of the petiole, no part of which exhibits any structure like that of a pulvinus.

From The Power of Movement in Plants by Darwin, Charles

At the base of the peduncle there is a mass of small cells, forming a well-developed pulvinus, which is exteriorly coloured purple and hairy.

From The Power of Movement in Plants by Darwin, Charles