Lichen, a composite organism composed of a fungus and a symbiotic photosynthetic partner, usually algae, appears plentifully in Tallon Overworld in Metroid Prime. The specific kind of lichen that grows on Tallon IV gives off low levels of radiation, and is unlisted in the Flora and Fauna Databank used by Samus Aran.
The fact that many indigenous Tallon IV species do appear in the databank, but the lichen does not, may indicate that the impact of a Phazon-laced meteor brought the radioactive lichen to the planet, or that it mutated the lichen beyond recognition, which would explain its radioactivity. The lichen is harmless to Samus and gives off a soft blue light.
- "This lichen appears to be giving off low levels of radiation. No matches found in flora and fauna databank." —Scan Data (Metroid Prime)
- "The stone surface this lichen grows on appears too smooth to be natural." —Scan Data (Metroid Prime)
- "Cannot identify light source. No profile matches in standard flora and fauna databank." —Scan Data (Metroid Prime)