[sawr-uh s, sohr-]
noun, plural so·ri [sawr-ahy, sohr-ahy] /ˈsɔr aɪ, ˈsoʊr aɪ/.
  1. Botany. one of the clusters of sporangia on the back of the fronds of ferns.
  2. Mycology. a soruslike spore mass of certain fungi and lichens.

Origin of sorus

1825–35; < New Latin < Greek sōrós heap Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for sorus

Historical Examples of sorus

British Dictionary definitions for sorus


noun plural -ri (-raɪ)
  1. a cluster of sporangia on the undersurface of certain fern leaves
  2. any of various similar spore-producing structures in some lichens and fungi

Word Origin for sorus

C19: via 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

sorus in Science


Plural sori (sôrī)
  1. A cluster of sporangia borne on the underside of a fern frond. A sorus is sometimes covered by an indusium. Also called fruitdot
  2. A reproductive structure consisting of masses of spores, characteristic of certain fungi such as rusts and smuts.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.