Chaenothecopsis nigripunctata, a remarkable new species of resinicolous Mycocaliciaceae from western North America.

The new species Chaenothecopsis nigripunctata (Mycocaliciaceae, Ascomycota) is described from western North America. The fungus grows on resin and wetwood of Tsuga heterophylla in moist temperate forests. It differs from its relatives in the regular production of polycephalic ascomata with contiguous capitula. The species is further characterized by a well-developed mazaedium. An unevenly thickened epithecium acts to compartmentalize the mazaedium into several columns per apothecial disk. Dark spore masses against the pale epithecium give the fungus a highly distinctive, elegant appearance. This species is not easily accommodated in Chaenothecopsis in a traditional sense but it is placed in this genus pending a better understanding of relationships within the Mycocaliciaceae.