UPPER SURFACE: shiny, smooth, greenish, emaculate, flat
LOWER SURFACE: dark brown to black, rhizines becoming v short and sparse near margins
LOBES: rounded, eciliate
SORALIA: granular, circular but becoming confluent in age
CHEMISTRY: cortex K-, KC+y; medulla K-, C-, P+r
Worldwide temperate to tropical.
Broad, greenish, appressed epiphytic foliose lichen. Lobes are smooth, rounded, flat, shiny, with black or grayish pigment usually showing around the margin (from pigmented lower cortex). Apothecia are rare; soralia on raised bumps in center of thallus.
On bark of mostly broadleaf trees, fenceposts, occ. rock.
I’m not sure what the fundamental difference is between Flavoparmelia and Xanthoparmelia. There is little overlap of habitat, but the former can grow on weathered wood and rock. The former is never isidiate, but the latter can rarely be sorediate, and of course both can be fertile. The anatomy of the cortex, the chemistry, and the ascospores and conidia all seem to be the same. Brodo claims rock-dwelling Flavoparmelia are typically broader-lobed and more wrinkly1. Also, all Xanthoparmelia I’ve seen are far more abundantly pycnidiate, especially the fertile ones.
