Patterns of biomass allocation to male and female functions in plants with different mating systems.

Using dry weight biomass we examined the patterns of investment in male and female functions (prezygotic cost) in plants with different mating systems. All the flower parts of both xenogamous and facultatively xenogamous species were heavier, i.e.

The pollination biology and breeding system of Monarda fistulosa (Labiatae).

Successful cross-pollination of Monarda fistulosa is the result of a complex interaction among flower opening, the pollen-bearing areas of the pollinators and/or their behavior, and the maturation of the stigmas. The flowers open continuously from 0800-2000 h providing a temporally predictable rich source of nectar and pollen. Recently opened flowers may reduce the ability of bees to discriminate between resource rich and poor patches and encourage systematic foraging within patches.