Here is some lichen and old man’s beard I found on a plein air excursion down the peninsula. Lichen is the result of a nice symbiotic relationship between green algae and a fungus. They are remarkably vulnerable to air purity and so are good indicators of air quality. When I drew this I didn’t know that “Old Man’s Beard” (I think: Alectoria sarmentosa) is just another kind of lichen. Also that bizarre neon-green stuff you see up in Tahoe and Yosemite. The fungus partner protects the chlorophyll-making algae when their environment gets too dry, and the algae provides the food. These lichens are in the dry state, as you can see by the delicate, pale green color. The green gets richer when there’s water for these guys—something rather scarce this winter until just this week.
