A cluster of odd saclike flowers bristles from the summit of a robust Yellowish Gentian, Gentiana alba. A few weekends back, while plumbing the depths of Adams County in southernmost Ohio for rare flora, the inimitable Daniel Boone showed us this station of gentians. Yellowish Gentian is quite the rarity here - listed as an Ohio threatened species - and I'd seen it only a few times prior.
If you are this flower, the whole idea is to get someone to bring you new pollen - pollen from another plant. Those lime-green stripes on the interior of the petals - petals are known as plaits in gentian-speak - help to lure in the pollen-delivering insect version of the UPS man.
But we don't have the eye-power of a bumblebee.
The photo above and the next two were taken by my friend Ethan Kistler, and show the process of a bumblebee invading a Closed Gentian, Gentiana clausa. In the first shot, the bee desperately seeks a path of entry into the flower, and quickly realizes that it must push itself into the tiny gap at the flower's summit. These are brutish, powerful insects, and that's what it takes to penetrate the gentian's defenses.
Just another of the scores of fascinating plant-insect relationships.