Darlingtonia californica Torr., a rare endemic plant species with patchy distribution in western Oregon and northern California, inhabits perennially wet seeps, often in serpentine soil. With the exception of studies made in the late 1800s by Rebecca Austin, the pollination biology of this plant is largely unexplored. The goals of this study were to classify stages of floral development in D. californica, to determine potential pollinators, and to correlate pollinator activity with floral development. The study was conducted at a fen near Eight Dollar Mountain in Josephine County, Oregon, over a 10-week period in the spring of 1996. Individual plants were marked and monitored until seed set. In addition, visitors to D. californica blossoms were observed and insects were collected using aerial netting and sticky traps; spiders were collected by hand. Acetolysis was used to identify pollen on all collected specimens. The results of this study suggest that spiders may play a role as pollinators of D. californica. Evidence also indicates pollination by several insect species.
Darlingtonia californica Illinois Valley floral development pollination spiders
