moss
/mɑs/
Any of various small, green, seedless plants growing on the ground or on the surfaces of trees, stones, etc.; now specifically, a plant of the phylum Bryophyta (formerly division Musci).
A kind or species of such plants.
Any alga, lichen, bryophyte, or other plant of seemingly simple structure.
Irish moss
A bog; a fen.
the mosses of the Scottish border