Two new species of true morels from Newfoundland and Labrador: cosmopolitan Morchella eohespera and parochial M. laurentiana.

Morphological and molecular phylogenetic studies of true morels (Morchella) in the Canadian province of Newfoundland and Labrador resulted in the discovery of two undescribed species in the M. elata clade that we initially distinguished by the informal designations Mel-19 and Mel-36. The latter species, also collected in New Brunswick, Canada, is hitherto known only from the St Lawrence River Basin. Mel-36 is described here as a novel, phylogenetically distinct species, M. laurentiana. Before the discovery of Mel-19 in Newfoundland and Labrador, New Brunswick and Washington state it was only known from central China and central and northern Europe. Mel-19 is described here as a novel species, M. eohespera.

Four new species of Morchella from the Americas.

Morphological and molecular phylogenetic studies of true morels (Morchella) in North America, the Dominican Republic, Venezuela, Ecuador, and Peru led to the discovery of four undescribed species of Morchella. Two new species in the Elata clade, one from the Dominican Republic, initially distinguished by the informal designation Mel-18, and a newly discovered sister species from northern Arizona, are now recognized. Mel-18 is described as a novel phylogenetically distinct species, M. hispaniolensis. Its sister species from Arizona is described as M. kaibabensis, also recovered as an endophyte of Rocky Mountain juniper. Two additional species in the Esculenta clade, M. peruviana discovered in Peru and M. gracilis (previously reported as Mes-14) from the Dominican Republic, Venezuela, and Ecuador, are described as new. We also demonstrate that scanning electron microscopy (SEM) imaging of ascospores using rehydration/dehydration/critical point drying preparation techniques provides for enhanced resolution of spore wall surfaces, thereby increasing the number of morphological traits available to assess differences among otherwise closely related species.

Polyozellus multiplex (Thelephorales) is a species complex containing four new species.

Geographic, morphological, and internal transcribed spacer (ITS)-based molecular review of collections identified as Polyozellus multiplex revealed that it is a complex of five phylogenetic species. Average spore size-either less or more than 7 × 6 µm-splits the complex into a small-spored group of two (P. multiplex and P. atrolazulinus) and a large-spored group of three (P. mariae, P. marymargaretae, and P. purpureoniger). Basidiocarps of the small-spored species are somewhat smaller than the large-spored ones, are various shades of blue, dark all the way to black, with brownish tomentum only in early growth, have dark context, and have pilei that tend to flare out at the edge. The large-spored species produce somewhat larger sporocarps, have light or lighter context than the pileipelis, and usually retain some brown on the mature pileipellis, the edge of which tends to curl like a cabbage leaf. All will darken or blacken with age. The species of the P. multiplex complex are distributed in the northern coniferous region, with the exception of Europe. One species (P. atrolazulinus) is known from three regions, eastern Asia, western North America, and northeastern North America. Two species are known from two regions: P. purpureoniger in eastern Asia and northwestern North America and P. multiplex in eastern Asia and eastern North America. Two species have been documented in one region only: P. mariae in northeastern North America and P. marymargaretae in western North America. A combination of location, macromorphology, and spore size will usually differentiate the species of the complex.