|
KING-IN-HIS-CARRIAGE ORCHIDS (2012)  acrylic on illustration board 15" x 7½" $3,600. |
For plants, sex is largely a crapshoot. Early flowering plants increased the odds of transferring their male gametes to a receptive ovary from the appropriate species by producing nectar to lure insects and other mobile animals that inadvertently transported pollen from one plant to another. This made it possible to invest less energy to producing masses of pollen, but producing nectar is also energy-intensive. Certain plants living in nutrient-poor conditions circumvented this problem by deceiving their pollinators. This strategy has become especially elaborate in the orchid family, where thousands of species rely on pollination vectors that are lured to the flowers by color or scent cues, without the nectar payoff. A European orchid genus and nine Australian ones use sexual deception. In these cases, a male wasp must try to copulate with the flower in order to pick up pollen and to transfer it as well. The flowers produce pheremones attractive to an insect; each orchid species attracts a different insect species. In some cases, the exact same compound is produced by orchid and wasp, and is found nowhere else in nature. The flower also bears some physical resemblance to a female insect. The little hammer orchids (Drakaea spp.) of southwestern Australia attract wasps of the family Thynnidae. The most widespread of the hammer orchids, the King-In-His-Carriage (D. glyptodon), grows in sandy heath and is pollinated by the wasp Zapilothynnus trilobatus. The flightless female wasp climbs a sedge blade or other plant when receptive, and waits for a flying male to whisk her off. Here she bears a modest resemblance to the warty dark labellum of the King-In-His-Carriage sitting atop its slender stem. When a male thynnid wasp attempts to carry off the flower's labellum, the hinged stem knocks the insect into the column, dusting the wasp or the stigma with pollinia. |