Squamules to 8 mm, erect. Upper surface green when dry, margins white. Lower surface white. K-. Apothecia red-brown, laminal. Upper cortex in section of anticlinal hyphae, with crystals showing in polarized light. No crystals seen in medulla or lower cortex. Lower cortex well formed, also of anticlinal hyphae. Medulla K-, C+ red, Upper cortex K-, C+ red. This matches Timdal's description in his 1986 Bryologist paper on Psora in North America. His treatment in the Sonoma book describes the upper cortex as thick walled with angular lumens.
Ken Kellman
2017-01-00
2017/01/28 2:51 PM PST
United States of America, California, Tehama County, CA, USA