Canoparmelia roseoreagens

This lichen has a grayish appearance and is sublaciniate, meaning it has irregularly branched lobes that are adnate (attached) and contiguous (touching), with truncate apices and a smooth to crenate margin. The upper surface is smooth and may have weak or absent maculae, which are reticulate (net-like), more evident in the young parts and may form small cracks. There are no lacinules, pustules or soredia. The isidia are concolorous with the thallus, cylindrical, and erect, ranging from simple to mostly coralloid, brown, and measuring 0.10–0.45 mm wide. The medulla is white and does not produce a purple pigment when treated with K. The lower surface is black to dark brown, slightly shiny, and rugose (wrinkled); the marginal zone is brown, shiny, and rugose (or sometimes papillate); the rhizines (root-like structures) are white, dark brown, or rarely black, simple to furcate (forked), 0.25–0.50 mm long, few to frequent, and almost evenly distributed. There are no apothecia (cup-like sexual reproductive structures) or pycnidia (small asexual reproductive structures).[2]

Canoparmelia roseoreagens contains several major lichen products: methyl olivetolcarboxylate, methyl divarinolcarboxylate, and eight unknown depsides that are derivatives of norsekikaic acid, norhomosekikaic acid, and norhyperhomosekikaic acids. The species epithet roseoreagens refers to the C+ (rose) chemical spot test reaction observed on the medulla.[2]