perispore
/ˈpɛrɪspɔː/Botany
noun
In early use: †a structure enclosing a group of spores, especially in an alga; a sporangium (obsolete ). Later: the outermost layer of the spore wall, or layer outside the spore wall, especially in ferns and mosses.
Origin
Mid 19th century (in an earlier sense). From peri- + spore, after French périspore.