Definition of "hymenium" [‖Hy•me•ni•um]

• The spore-bearing layer of the fruiting body of certain fungi, containing asci or basidia. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The cap of a basidiomycete, an expanded structure at the top of the stipe that bears the hymenium (gills, etc.) on its undersurface."
• "It is called from the prickly appearance of the under surface, or _hymenium_, the hedgehog mushroom"
• "Every mushroom has a spore-bearing layer of cells, which is called the hymenium."