Clonality and the mechanisms by which populations become established can affect the level and pattern of genetic diversity, which can in turn affect the ecology and evolution of those populations. We used amplified fragment length polymorphisms (AFLPs) to examine genetic diversity and clonality in four isolated populations of the rhizomatous pale pitcher plant, Sarracenia alata Alph. Wood, with particular emphasis on determining the extent of clonal spread and the likely mechanisms by which these populations became established. Genetic variation was greater within (87%) than between (13%) populations. The interpopulation genetic differentiation was a function of geographic distance. The mean (± SE) genetic diversity (H_E) within populations was 0.126 ± 0.006, and the percentage of polymorphic loci within populations ranged from 58.9 to 72.4% (64.3 ± 2.89, mean ± SE). We found no repeated multilocus genotypes among our samples, nor was there evidence of bimodality of genetic differences among individuals within populations. Significant spatial genetic correlation was generally found only within 1 m, and matrix incompatibility analysis indicated that more than 90% of the genetic differences among individuals within each population could be explained by recombination. Our results indicate that asexual spread by this species is minimal. The relatively high genetic diversity within populations, the low differentiation among populations, and the low probability of gene flow among current populations suggest that the study populations are most likely the remnants of populations that were formerly more widespread with greater probability for gene flow.