RHIZOIDS (from Gk. ῥίζωδής, rhizōdēs, root-like). Colorless, hair-like structures developed by liverworts, certain algæ, mosses, and fungi (toadstools and molds). Their function is to anchor the plant in favorable situations and in some cases perhaps to absorb water. The ferns have rhizoids only in connection with the very small prostrate sexual plant (gametophyte, q.v.).