Evidence for high rates of self-fertilization in the alpine herb Epilobiumanagallidifolium (Onagraceae)

Epilobium anagallidifolium Lam., alpine willow-herb, is a small perennial h erb found growing along the moist creek sides of recent snow runoff in alpi ne regions. The floral morphology of E. anagallidifolium, in which the anth ers rest neatly atop the stigma when the flower is closed, indicates this s pecies may regularly self-fertilize. We determined the mating system of thi s species by analyzing allozyme loci from 240 individuals in 20 different f amilies (12 individuals per family) for two polymorphic enzymes: PGI and MD H. In every family studied, all of the individuals within a family were hom ozygous for the same alleles. These data support the hypothesis that Epilob ium anagallidifolium reproduces primarily through self-fertilization, altho ugh we cannot rule out the possibility of occasional pollinator-mediated cr oss pollination.