JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Pollination biology at the community level was investigated using quantitative techniques, comparative methodology, measurements of the physical habitat, and consideration of floral characteristics. The frequency of insect visits to flowers was investigated in three contrasting communities: a deciduous woodland-meadow site in eastern Massachusetts, alpine tundra in New Hampshire, and Mediterranean scrub (fynbos) in South Africa. Visits to flowers were most common in woodland-meadow, followed by alpine tundra, and least frequent in fynbos. Bees were the most common visitor in the woodland-meadow and the fynbos, but flies were the most common visitor in the tundra. Flower color often influenced visitation rates and had a weak but significant effect on the type of insect that visited flowers. Preferences for color by different types of insects often changed in different communities, which suggests that floral syndromes may be communityspecific. In all communities, tubular flowers were visited less often than open flowers. Less specialized insects were more common on open than tubular flowers, but large variances made few differences statistically significant. Combining measurements of temperature, light, humidity, wind speed, time of day, and season (using cluster analysis) with the shape of a flower, it was predicted that a 1 0-minute observation would include at least one visit. Flower shape, temperature, light, and season appear to be the most important variables influencing insect visitation rates. Results of this study indicate that relationships between insects and flowers are nonspecific and vary among communities.Pollination biology is currently undergoing a renaissance because of its importance in understanding plant breeding systems, floral evolution, foraging theory, and animal behavior. Although most recent work has concentrated on single plant species, a number of communitylevel studies of pollination biology have also been undertaken (Kevan