usually persistent; small, up to 4 mm by 2 mm, irregularly or pal-mately divided, crenate, usually becoming concave; upper side glaucescent or olive-green or whitish glaucescent; underside white, darkening toward the base; esorediate or sparingly granulose. Podetia from the upper side of the primary squamules, 10-40 mm tall, up to 2.5 mm in diameter, cylindrical, cupless, simple or subsimple, dichotomous to trichotomous; the tips which bear apothecia dilated, those which are sterile blunt or subulate; the sides entire or fissured, sparingly granulose sorediate; cortex verruculose, the verruculae dispersed, partly developing into small squamules; the upper part of the podetium with reflexed, squarrose squamules similar to the primary squamules, the lower part becoming entirely squamulose, the part between the squamules decorticate; dull and not translucent, white or ashy or ashy brown, the verruculae and squamules white or ashy or olive-glaucescent. Apothecia
middle-sized to large or often small, confluent or lobate-fissured, dark brown or red-brown. Pycnidia
on the upper side of the primary squamules and the base of the podetia.
Reactions: K— , KC— , P— .
Contents: perlatolic acid.
This species grows on soils which are sandy as well as on those rich in humus. It is circumpolar, arctic, and boreal, but not high arctic. In North America it ranges south to Connecticut, New York, Wisconsin, and Colorado.