Indusium

‖n.; pl. Indusia [ L., an under garment, fr. induere to put on: cf. F. indusie the covering of the seed spots of ferns. ] (Bot.) (a) A collection of hairs united so as to form a sort of cup, and inclosing the stigma of a flower. (b) The immediate covering of the fruit dots or sori in many ferns, usually a very thin scale attached by the middle or side to a veinlet. (c) A peculiar covering found in certain fungi. [ 1913 Webster ]