Acarospora brodoana K. Knudsen, Kocourk. & M. Westb. is described from the San Bernardino Mountains in southern California. A black hypothecium distinguishes it from other species with a carbonized epihymenium. Sarcogyne albothallina K. Knudsen, Wheeler & M. Westb. is described from the Missouri Breaks in Montana. A white non-farinose thallus and production of 4-O-methylhiascic acid distinguishes it from other species with a carbonized epihymenium. Both species would previously have been placed in Polysporina. The current reported diversity of Acarosporaceae in North America north of Mexico is 93 species.
