Clarion Call--Part 2

The first English colonists to land in Virginia in the early 1600s were enchanted by the flashy trumpet vine blooms. They sent seeds back to England—presumably earning the enduring enmity of the fussier British gardeners. The vine is native to southeast United States, but like kudzu, it happily and obnoxiously thrives in many foreign sites. When I surfed the web for information on the vine, nearly as many websites offered suggestions for eradicating it, as described its attraction for hummingbirds. I like it because it masks the view of the ugly outbuildings, but also looks very attractive—to say nothing of the enjoyment I get watching pollinators come for a nectar sip.

Nectar is a sugar-rich liquid that many blossoms secrete, to attract hummers, bees, butterflies, and other pollinators. It is much more than the bland sugar water that we fill our hummingbird feeders with. The plants have evolved a clever technique of adding smelly chemicals to the nectar that emit attracting aromas to flying critters who have a sweet tooth. But nectar has even more goodies: a complex blend of many amino acids that constitute protein. So a hummer not only gets a sugar high, but ingests crucial protein. When a hummer’s sweet diet consists primarily of human offerings of sugar water in a feeder, the bird must supplement this diet by finding tiny spiders and insects for its protein. I doubt that I could come up a balanced diet as good as nectar, even if I were to try to find some way to add a pinch of amino acids to my feeder.

Of course, the flower’s sweet gift is not solely a generous gesture to pollinators. It requires some energy on the part of the plant to manufacture nectar—something it really doesn’t need for itself. But it does need to have its pollen transported from bloom to bloom, in order to inseminate its reproductive structures, and it hasn't yet evolved to fly. The (humming) birds and the bees do that for it. When the hummer ducks its head into a blossom, it withdraws it coated with pollen. When a bee waddles down inside, it must brush against the flower’s reproductive organs, coating itself with pollen in the process. It’s a wonderful example of one of nature’s symbiotic relationships—an interaction between two different organisms, to the advantage of both.

The bloom time for the trumpet vine is just a few weeks in late July. There is no other nectar-offering plant close to my outdoor tub. I think I’ll want a bath more often at this time of year, just so I can get more of the aerial pollination show.