Thompson, J., 1984. American Arctic Lichens: The Macrolichens.
Primary squamules persistent, small to middle-sized, up to 3 mm long, crenate to lobed; upper side glaucescent to olive-glaucescent; underside white to darker at the base; esorediate or more commonly sorediate at the margin and on the underside. Podetia growing from the upper side of the primary squamules; varying in height up to 50 mm but usually smaller, up to 10-20 mm; commonly broadening slightly to the blunt tip, producing a club-shaped podetium, rarely sharp-pointed, usually covered with greenish farinose soredia, the base with only a very short corticate patch, white throughout after dispersal of soredia although in one form with yellowish spots which turn violet with K. Apothecia scarlet, small to medium-sized, up 2 mm; often imbedded in the tips of the podetia. Pycnidia on the surface and margins of the primary squamules.
Reactions: K-, KC- or KC+ yellowish. P-.
Contents: barbatic acid with accessory' usnic and didymic acids and F.
This species grows on old logs, tree bases, earthen banks, and humus. It is cosmopolitan, in North America being low arctic boreal and temperate, ranging over most of the United States.