Myxomycetes collected in the eastern United States and patterns of relative biodiversity.

A total of 68 315 digitised records of myxomycetes from the eastern United States were compiled from all readily available sources. After cleaning the database for inconsistencies, 58 594 records remained that were suitable for analysis. A total of 460 different species of myxomycetes were recorded, out of which 410 were classified as rare. Five species were represented by more than 1 500 records and 44 species were represented by only a single record. The states of New York, Virginia and West Virginia have the highest number of records. Almost half of the recognised morphospecies of myxomycetes in the world occur in the eastern United States. A small number of species thrive in different ecological conditions, whereas most species require more specific ecological settings for the formation of fruiting bodies. States associated with high biodiversity have been subjected to more intensive sampling efforts, and southern states seem to have been less studied than northern ones. The project described herein apparently represents one of the few efforts to characterise the myxobiota of a relatively large region of the world.