Slideshow image
Pertusaria alaskensis Erichsen
Family: Pertusariaceae
Pertusaria alaskensis image
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus ash-gray or white, over rocks, thick to very thick, even lifting off substratum, margin entire and not zoned, surface smooth to rough-folded, shining or dull, lacking soredia or isidia. Fertile verrucae of same color as thallus, base narrowed, flat-topped or hemispherical, dispersed or crowded, to 3 mm broad; margins thickened or sometimes split or crenulate; ostioles 1—3(—5) per verruca, usually sunken, sometimes broadening and fusing to form a pseudolecanorate disk. Apothecia up to 6 per verruca but usually less, center hyaline to pink or red; epithecium dark brown or black, K+ strongly violet; asci clavate or cylindrical; spores 4 (occasionally 2, 3, or 5), biseriate or uniseriate, ellipsoid to fusiform, outer wall 1-5 μm.

Contents: gyrophoric acid, ± lecanoric acid and traces of unknowns.

This species grows over humus and moss over soil and rocks. It is apparently an amphi-Beringian, according to Dibben (1980), although it occurs in the White Mountains in New Hampshire, in the East.