hymenium n 1: spore-bearing layer of cells in certain fungi containing asci or basidia
Hymenium \Hy*me"ni*um\, n.; pl. L. {Hymenia}, E. {Hymeniums}. [NL., fr. Gr. ? a membrane.] (Bot.) The spore-bearing surface of certain fungi, as that on the gills of a mushroom. [1913 Webster]