Wahlenbergiella tavaresiae

About

Wahlenbergiella tavaresiae is a species of saxicolous (rock-dwelling), crustose lichen in the family Verrucariaceae. Known from several locations in the San Francisco Bay area of the United States, it is a marine lichen that inhabits intertidal zones, and as such is immersed in seawater on a regular basis. Associated algal species include the red algae Hildenbrandia and Mastocarpus papillatus, and the brown algae Pelvetiopsis and Fucus. Petroderma maculiforme, a brown alga, is the photobiont partner in the lichen.

Summary from Wikipedia