noun
- plural of indusium; a membranous covering or flap that protects the sorus (cluster of sporangia) in ferns
Usage: botany; technical term
Examples
- The indusia of the fern frond curl back to reveal the mature sporangia.
- Botanists examined the indusia under a microscope to identify the fern species.
- The shape and position of indusia are important characteristics for fern classification.
- As the fern matures, the indusia gradually shrivel and expose the spore-bearing structures.