pulvinus

[ puhl-vahy-nuh s ]

/ pʌlˈvaɪ nəs /

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

Examples of this are furnished by the cardiac muscle of the animal, the pulvinus of Mimosa, and the stamen of Berberis.

Life Movements in Plants |Sir Jagadis Chunder Bose
This is seen in the response of the pulvinus of Mimosa to light acting from above.

Life Movements in Plants, Volume II, 1919 |Sir Jagadis Chunder Bose
The intensity was increased to a suitable value by focussing light on the upper half of the pulvinus by means of a lens.

Life Movements in Plants, Volume II, 1919 |Sir Jagadis Chunder Bose
The result is seen in the above record (Fig. 19), where water was applied on the pulvinus after the second response.

Life Movements in Plants |Sir Jagadis Chunder Bose

I was thus able to secure specimens which were far more sensitive to the action of electric waves than the pulvinus of Mimosa.

Life Movements in Plants, Volume II, 1919 |Sir Jagadis Chunder Bose

pulvinus

/ (pʌlˈvaɪnəs) /

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