  |
|
|
|
As far as wildflowers are concerned, this past year has been an adventure in paradise for me. Spring in the mountains of Western North Carolina was like living in the depths of a Horn of Plenty: vaguely familiar faces with all new names. And here in the Sierra Nevada Mountains it is like starting over: new wildflower species at every turn. But what have been relentless in floating to the top of the heap are the orchids.
The Orchid Family is the largest family of flowering plants in terms of species - more than 20,000, in perhaps 700 genera. They are most abundant in the tropics where they typically grow on other vegetation. North American orchids are terrestrial. Some species, once very rare and difficult to obtain, are now reproduced in great numbers by cloning. Others, perhaps, are still out there waiting to be discovered. Orchids are notoriously tricky where pollination is concerned and insects often have to go through a specific song and dance for pollination to take place. Nodding Ladies’ Tresses, for example, have flowers which distribute pollen, and flowers which receive pollen on the same plant. The lowest flowers on each floral spike are the oldest, and have matured to the point where they are designed to receive pollen and be fertilized. The newer flowers, higher up on the spike, are less developed , and can only give pollen. Consequently, as a bee moves down the spike of flowers, it picks up pollen grains first, and then pollinates the lower flowers. Showy Lady’s Slippers (C. reginae) are a little more demanding. The lower petal of the flower has evolved to become a sac-like structure which, with the vein-like lines that surround the opening to entice passers-by, is attractive to bees. The edge of the opening curves downward into the sac, making it more difficult for a bee to leave the flower once inside. This chamber is lined with hairs, many of which secrete a sweet nectar, that lean toward an opening at the rear. As if heeding the words of a spiritualist in a bad horror movie, the bee moves toward the light of the opening, working its way through the nectar. The bee, before finally exiting the flower, rubs against the stigma, which is shaped like a comb to remove pollen. It then rubs against the anthers, which paint the hapless insect with pollen in a quick-drying semi-liquid form. So, when a bee finds itself lured into a second flower, the pollen from the first is scraped off, fertilizing the blossom, and a new coat of pollen is wiped on. |
|
|
|
