[suh-ree-dee-uh m]
noun, plural so·re·di·a [suh-ree-dee-uh] /səˈri di ə/. (in a lichen)
  1. a group of algal cells surrounded by hyphal tissue, occurring on the surface of the thallus and functioning in vegetative reproduction.

Origin of soredium

1820–30; < New Latin, diminutive of Greek sōrós a heap
Also called brood bud, hologonidium.
Related formsso·re·di·ate [suh-ree-dee-it, -eyt] /səˈri di ɪt, -ˌeɪt/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for soredium


  1. an organ of vegetative reproduction in lichens consisting of a cluster of algal cells enclosed in fungal hyphae: dispersed by wind, insects, or other means

Word Origin for soredium

C19: New Latin, from Greek sōros a heap
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012