noun, plural so·ri [sawr-ahy, sohr-ahy] /ˈsɔr aɪ, ˈsoʊr aɪ/.
Botany. one of the clusters of sporangia on the back of the fronds of ferns.
Mycology. a soruslike spore mass of certain fungi and lichens.
Origin of sorus
1825–35; < New Latin < Greek sōrós heap
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for sori
Historical Examples of sori
The sori are borne in lines on either side of the mid-vein of the lobe.
We shall find the sori on veins which run from the mid-vein of the pinnules.
The sori are placed on veins which branch out from the mid-veins of the pinnules.
The sori are very abundant, but as these are small they should be carefully examined.
The sori have indusia, but this is hidden by the margin of the pinnules, which are recurved.
British Dictionary definitions for sori
noun plural -ri (-raɪ)
a cluster of sporangia on the undersurface of certain fern leaves
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
Plural sori (sôr′ī)
A cluster of sporangia borne on the underside of a fern frond. A sorus is sometimes covered by an indusium. Also called fruitdot
A reproductive structure consisting of masses of spores, characteristic of certain fungi such as rusts and smuts.
The American Heritage® Science Dictionary
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