U.S.A., Arizona, Cochise, Chiricahua National Monument, Paradise Canyon, a small tributary of Bonita Canyon just east of Monument Headquarters.
On sloping top of huge stream boulder, in shade, plants loosely attached.
Easily scraped off by a knife; two species intermixed here, the majority of the thalli have pale undersides; those with dark undersides are P. taemanica Hook. f. et Tayl. Substrate: saxicolous.