It covers the trunks and branches of oaks and Monterey Cypress with an orange flocking.
Trentepohlia aurea is filamentous terrestrial green alga whose orange coloration comes from carotenoid pigments in its cells.
Susan Hanlon was visiting Point Lobos State Park on the Monterey Peninsula when she was impressed by its bold orange display.
Point Lobos is most famous for Trentepohlia, though the alga is commonly found in humid areas along the California coastline including the San Francisco Bay Areas, Great Britain and Ireland.
Although not technically an autumn color, it shares orange carotenoid pigments with autumn leaves.
