Placopsis is represented by three species in North America: P. gelida, P. cribellans and a new species found principally on the Queen Charlotte Islands, B. C. The new species, named here as P. roseonigra, is characterized by a non-lobate, dispersed areolate thallus developing on a paracephalodium-like bed of cyanobacteria (Stigonema). Its apothecial and ascal features clearly place it into the Trapeliaceae, but its generic position is less clear since it shares some characteristics of Placopsis and others of Trapelia