Physcia millegrana
Physcia millegrana photo by Ray Showman
Physcia millegrana photo by Bob Klips
Physcia-millegrana-and-Candelaria-concolor photo by Bob Klips
DIAGNOSTIC FEATURES: Margins a mass of linear soralia; tips much dissected; central tips ascending, often forming a concave cushion of bluish-white soredia; cortex K+, medulla K-; compare with Phaeophyscia spp. which are greenish, and have surface soralia. Cladonia primary thallus can sometimes be mistaken for this species.
ECOLOGY: Found throughout the eastern US; undoubtedly the commonest foliose lichen in Ohio with records from every county. A pioneer species that is frequently the first to colonize the stem and branches of young woody plants, it is also found, though more rarely, on rock. This species is tolerant of air pollution and can withstand the adverse microclimate of cities. It is sometimes the only macrolichen found in downtown areas