Graduate student Tobias Policha has long had a dual love affair with plants and the open road. He satisfied both of these passions last spring and winter on a five-month stint in a remote cloud forest reserve in the Ecuadorian Andes, where he studied one of nature’s most fascinating cases of deception.
The cloud forests in Ecuador are internationally famous for their stunningly diverse species of orchids, which thrive in the moist and balmy terrain. One of these flowers, the Dracula orchid (above), is the object of Policha’s doctoral research.
The Dracula orchid apparently has adapted to its home by mimicking small native mushrooms. Not only do the lips of the flower visually resemble the fungi but the flowers also emit a scent that is chemically similar to the mushrooms’. Policha’s hypothesis is that the Dracula orchid, and possibly other orchids, have evolved in this way to attract mushroom flies and thus increase their chances of pollination.
“Deceptive pollination strategies are quite common in the orchid family, but it’s pretty unusual that they imitate a mushroom,” said Polica (collecting DNA in the photo at left). “But just because there’s mimicry doesn’t necessarily mean there’s an evolutionary advantage.”
To prove his theory, he and his research partners hiked through steep, muddy terrain several hours a day to reach the sites where both mushrooms and orchids flourish. Once there he collected a trove of data by spending hours observing how many flies visited particular orchids and fungi, collecting hundreds of specimens (600 mushrooms and 300 flies) and extracting fragrance samples that will allow him to analyze the odor of the flora.
He hopes to have analyzed all of this by the next field season in January. Preliminary results have shown distinct chemical similarities between at least one orchid and mushroom pair.
Policha also theorizes that the chemical makeup of the flowers attracts very specific visitors and pollinators, which could explain why many species persist within very strict boundaries.
The privately owned forest where he is conducting his research is a five-hour mule ride from the closest town. Known as La Reserva Los Cedros, it is home to innumerable species of birds and other fauna, including the critically endangered brown-headed spider monkey. Policha hopes that his work with the orchids will help validate the superlative uniqueness of the forest’s biodiversity and keep it protected from mining and logging interests.
“You have to inspire people,” he said. “And these orchids are unique and intriguing. Maybe with greater understanding they could be the poster flowers for conservation efforts.”
— Marc Dadigan
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