Assertion: fern's structure | /r/HasProperty | indusium
Facets:
Source sentences:
text: In addition, some sporangia are protected by a little membranous structure (an indusium), and others aren’t.
text: Characteristic of the genus are curved or horseshoe-shaped spore-producing clusters (sori) that are covered by a fringed, membranous protective structure (indusium).