Mixes of Algae and Fungi That Grow on Rocks

This page is the CodyCross answer for the clue below from Underground Worlds, Group 2171, Puzzle 1 (Chislehurst Caves).

Question is: Mixes of Algae and Fungi That Grow on Rocks

and the answer is: LICHENS

Word Meaning:

LICHENS — plural of lichen

Definitions from Wiktionary.