Representative collections of Flammulina were examined by restriction diges
ts of the ribosomal RNA internally transcribed spacer region (ITS1-5.8SITS2
). Digestion with the restriction enzymes, HaeIII and Bst F51 distinguished
among the major Northern Hemisphere species of Flammulina. Digestion of F:
velutipes collections with two additional restriction enzymes, Bgl I and B
st UI, gave variable restriction fragment patterns and revealed biogeograph
ically identifiable patterns. Three haplotypes of F. velutipes were identif
ied with geographical distributions chiefly in Asia, Europe and North Ameri
ca. Recent transfer of haplotypes among geographical areas seems plausible
based on the observed haplotype distribution.