A Lichen, Parmelia sulcata

This lichen is Parmelia sulcata, a common species in North America.   Lichens -- which are often mistaken for moss -- are unusual plant-like organisms that are actually symbioses of fungi, algae and bacteria living together. They usually live on soil, bark, leaves and wood and can live in barren and unwelcoming environments, including the Arctic and in deserts. Lichens produce unique and unusual organic compounds that aid their survival and can have antibiotic, antiviral and other chemotherapeutic activities.