so·​rus ˈsȯr-əs How to pronounce sorus (audio)
plural sori ˈsȯr-ˌī How to pronounce sorus (audio)
: a cluster of plant reproductive bodies: such as
: a cluster of sporangia on the underside of a fertile fern frond
: a mass of spores bursting through the epidermis of the host plant of a parasitic fungus
: a cluster of gemmae on the thallus of a lichen

Examples of sorus in a Sentence

Recent Examples on the Web Last fall, divers couldn’t find any sorus tissue in the usual spots. Carol Leonetti Dannhauser, Hartford Courant, 27 May 2022 Just 4 pounds of sorus can seed 30,000 pounds of kelp for harvest., 26 June 2021 Fishermen place spore-holding sorus tissue along lengths of rope and submerge them, letting Mother Nature do the rest., 26 June 2021

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sorus.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


New Latin, from Greek sōros heap

First Known Use

1832, in the meaning defined above

Time Traveler
The first known use of sorus was in 1832

Dictionary Entries Near sorus

Cite this Entry

“Sorus.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2024.

Kids Definition


so·​rus ˈsōr-əs How to pronounce sorus (audio)
plural sori ˈsō(ə)r-ˌī How to pronounce sorus (audio)
: any of the dots on the underside of a fertile fern frond consisting of a cluster of spores

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