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Sorus
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A botanical diagram shows different types of sori and sporangia arrangements in various fern species, including labeled cross-sections and surface views for genera such as Pityrogramma, Pteris, Polypodium, Acrostichum, Asplenium, and Dryopteris.
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Plural:
sori
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A botanical diagram shows different types of sori and sporangia arrangements in various fern species, including labeled cross-sections and surface views for genera such as Pityrogramma, Pteris, Polypodium, Acrostichum, Asplenium, and Dryopteris.
sori Examples of sori and arrangements of sporangia in various species of ferns.

Sorus

plant anatomy
Also known as: sori
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•History

Sorus, in botany, brownish or yellowish cluster of spore-producing structures (sporangia) usually located on the lower surface of fern leaves. A sorus may be protected during development by a scale or flap of tissue called an indusium. In rust and smut fungi, a sorus is a spore mass produced on the leaf of an infected plant. Reproductive structures called sori also occur in various species of marine algae. See also spore.

This article was most recently revised and updated by John P. Rafferty.