1In certain lichens, especially ones of the genus Parmelia: any of a number of spongy, sometimes highly branched, outgrowths arising from the thallus.
2= pulvinule .
Early 19th century; earliest use found in John Loudon (1783–1843), landscape gardener and horticultural writer. From scientific Latin pulvinulus from classical Latin pulvīnulus (former reading at Columella De Arboribus 10. 4, where modern editions have pulvillus) from pulvīnus cushion, pillow + -ulus.