sorus

American  

[sawr-uhs, sohr-] / ˈsɔr əs, ˈsoʊr- /

noun

plural

sori

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.

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sorus British  

/ ˈsɔːrəs /

noun

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

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sorus Scientific  

/ sôr′əs /

plural

sori

1. A cluster of sporangia borne on the underside of a fern frond. A sorus is sometimes covered by an indusium.

2. Also called fruitdot

3. A reproductive structure consisting of masses of spores, characteristic of certain fungi such as rusts and smuts.

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Etymology

Origin of sorus

1825–35; < New Latin < Greek sōrós heap

Example Sentences

Here is a closeup, showing the fern sori I discussed here: Because I just can’t get enough of gorgeous and unusual ferns, here are some more.

From Scientific American

When you look at the back of a fern, you might think you are looking at a pile of spores Fern sori, a collection of microscopic but structurally complex sporangia.

From Scientific American

Sori linear, confluent in pairs, each pair appearing like a single sorus with a double indusium opening down the middle.

From Project Gutenberg

The pustules, or sori, break through the cuticle in a similar manner, and here also no true peridium is present.

From Project Gutenberg

This occasionally happens from the elongation of the normally placed sorus, which thus extends to the margin, and returns on the upper side, when the sori chance to be placed opposite to the marginal crenatures.

From Project Gutenberg