The results of a series of experiments and field observations indicate that bumble bees are the chief pollinators of Chelone glabra L. var. glabra, but that their activity may lead frequently to geitonogamy and less often to xenogamy. Flowers from which corollas were removed failed to attract bees and did not produce seed. Flowers that were unaltered but shielded from insect visitation also failed to produce seed. Seeds were produced on plants cross-pollinated by hand. Seeds were also produced after pollination of stigmas with pollen from their own inflorescence. This facultative geitonogamy is likely a contributing factor to the geographical distribution pattern of the variety, a pattern characterized by relatively isolated colonies
