wet fallen branch Bigleaf Maple, West Seattle medulla K+yellow white splotches are "maculae" - areas lacking the green photobiont layer which is visible through the cortex Brodo, I. M., C. Freebury & N. Alfonso. 2013. Notes on the lichens Physcia aipolia and Physcia alnophila in North America. Evansia 30: 110-119. Practical advice on using morphological and chemical characters to separate the recently recognized P. alnophila from P. aipolia. The dominant taxon in the PNW is P. alnophila. also see www.sekj.org/PDF/anb46-free/anb46-043.pdf my lichen photos by genus - www.flickr.com/photos/29750062@N06/collections/7215762439... my photos arranged by subject, e.g. mountains - www.flickr.com/photos/29750062@N06/collections