Related Clues:
- In speech, compare fungus and alga
- Composite plant right outside church
- Reindeer moss, e.g
- Fungus/alga symbiosis
- Primitive plants found on rocks
- What a rolling stone is unlikely to gather
- Chile cultivated new plant
- Algae-fungi composite
- Bark missing from branch-like, mossy growth
- Church in place that's not on top of mossy growth
- Plant of rocks and walls
- Growth on a tree
- Growth found on tree trunks and rocks
- Litmus source
- Reindeer moss, for instance