Abstract
The few studies that have investigated levels of genetic variation in liverworts have found very little polymorphism. Our electrophoretic data show, however, that the leafy liverwort Porella platyphylla maintains high levels of genetic variation in at least some natural populations from the southeastern United States. Within a single population from southwestern North Carolina, we detected 26 distinct multilocus genotypes and more than 80% of the enzyme loci we surveyed were polymorphic. It seems likely that earlier studies of mostly thalloid species from glaciated regions of Europe have presented a biased picture of levels of variation in liverwort populations.