Trentepohlia aurea

Trentepohlia aurea is a filamentous green alga that forms conspicuous orange to reddish patches on bark, rock, and other exposed surfaces in humid environments. Its green chlorophyll is masked by abundant orange carotenoid pigments. The fine branching filaments spread into velvety mats and may also occur as the photosynthetic partner in lichens. Photographed in Colombia.