Excerpts from Jim Conrad's
from the September 4, 2011 Newsletter
issued from Mayan Beach Garden
Inn 20 kms north of Mahahual, Quintana Roo, México
In that picture you can see that some corolla lobes are more up-turned than others. This makes the corolla bilaterally symmetrical instead of radial. If you looked down the corolla's throat you'd see four male stamens arching up to the corolla tube's ceiling, with the female style and stigma running along the tube's floor. That's a perfect configuration for a pollinator entering the flower to have pollen dumped on him from above even as he delivers pollen from other flowers on his underparts.