Monterey Cypress Algae (Trentepohlia)
Trentepohlia is a genus of filamentous green chlorophyte algae which lives on tree trunks and wet logs. The strong brownish-orange color of the filaments, which mask the green of the chlorophyll, is caused by the presence of large quantities of carotenoid pigments, a pigment that also occurs in carrots. I came across this tree at the end of the marina right across from the state park museum in Morro Bay. I can not believe that this algae is very good for the tree in that it covers up the lenticels (holes in the trunks similar to stomata in the leaves), so the exchange of gases would surely be reduced. I do not know if it will kill the tree or not yet, but some have stated so.