Hooded Tube Lichen

Thallus: appressed, up to 6 (-8) cm broad; texture: cartilaginous; branching: isotomic dichotomous, budding occasional; lobes: contiguous to imbricate or ± separate, 0.5-2.5 (-4) mm broad; black border: not visible from above; profile: even to irregular; width/height ratio: 1-4; tips and axils: entire or torn; upper surface: white, gray to greenish gray, dark mottles none or rare, occasionally rugose; soredia: on the inside of the burst lobe tips, appearing as if in labriform soralia; isidia absent, lobules rare; medulla: hollow, ceiling of cavity white or dark, floor of cavity dark; lower surface: black, rarely perforate; Apothecia: rare, substipitate to stipitate, up to 2 (-4) mm in diam; stipe: funnel-shaped, hollow; disc: brown; ascospores: ellipsoid, 7-8 x 4.5-5.5 µm; Pycnidia: occasional; conidia: rod shaped, 5.5-5.8 x 0.5-0.6 µm; Spot tests: cortex K+ yellow, C-, KC-, P+ pale yellow, UV-; medulla K-, C-, KC+ orange-red, P+ orange-red.; Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with physodic acid (major), 2'-O-methylphysodic acid (minor or accessory), 3-hydroxyphysodic acid (major), physodalic acid (major), and protocetraric acid (minor).; Substrate and ecology: on bark or wood including conifers and hardwoods, rarely on rock, moss, or alpine sod.