Fern sorus. Fluorescence light micrograph of a sorus on the underside of a fern frond. A sorus is a cluster of spore-producing receptacles called spor

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Fern sorus. Fluorescence light micrograph of a sorus on the underside of a fern frond. A sorus is a cluster of spore-producing receptacles called sporangia (blue and green). Each sporangium is packed with spores (brown), which are the fern's reproductive cells. A rim of thick-walled cells, the annulus (green), functions to open and rapidly close each sporangium when the spores are mature, releasing them into the environment.

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Size: 4128px × 3000px
Photo credit: © ROGELIO MORENO/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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