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.

---

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

---

Etymology

Origin of pulvinus

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

Example Sentences

What makes the sunflower such a puzzle is that it belongs to a group of flowers that lack what is known as a pulvinus—a thickening at the base of a leaf or other structure that changes its rigidity in response to light.

From Time

As the sun moves across the sky, different amounts of water flow into different parts of the pulvinus, nudging the leaf in the sunniest direction.

From Time

The pulvinus of this capital is ornamented with leaves, as 263 in the example from Athens in B�tticher's Tektonik, pl.

From Project Gutenberg

It was not a column, it was a pulvinus, or volute, of a colossal marble altar, worthy of being compared, in size and perfection of work, with the Altar of Peace discovered under the Palazzo Fiano, with that of the Antonines discovered under the Monte Citorio, and with other such monumental structures.

From Project Gutenberg

They are articulated to the petiole, and the petiole to the branch by a pulvinus.

From Project Gutenberg