clika gismu

x1 is a moss/lichen of species/strain x2 growing on x3; (adjective:) x1 is mossy.

See also mledi.

In notes:

mledi
x1 is a mold/fungus/mushrooms/truffles of species/strain x2 parasitic/growing on x3.
alge
x1 is algae of species/variety x2
cma'alge
x1 is a diatom of species/variety x2