Smithsonian.com

A fly pollinating a Satyrium pumilum orchid (Credit: Dennis Hansen)

Scientists studying a South African orchid determined, with the clever use of roadkill, that the flower attracts pollinators by mimicking the scent of carrion. Their report appears in the Annals of Botany.

The Satyrium pumilum orchid grows in sandy, moist soil near streams in South Africa. Unlike most flowers, S. pumilum doesn’t have any nectar that would attract pollinators. But the flowers do somehow attract flies. And when the scientists placed near the orchids the carcass of a rock hyrax retrieved from a roadside, they found that a lot of the flies were carrying orchid pollen.

Further experiments revealed that the orchids were indeed producing a carrion-like scent, though it was relatively weak. But that was the perfect amount to attract flesh flies that prefer small carrion. The scent is close enough to the real thing that female flesh flies will sometimes even deposit their larvae on flowers instead of in a dead animal.

“What we’ve done is show for the first time that carrion-mimicking flowers are highly sophisticated tools for orchids,” said the study’s lead author, Timotheüs van der Niet of the University of KwaZulu-Natal in South Africa. “It also disproves a cliche—you don’t always catch more flies with honey.”

The concept of collecting and protecting seeds and plants for research and to preserve biodiversity got its start in Russia. Russian botanist Nikolai Vavilov created the world’s first seed bank, collecting fruit and vegetable seeds from across five continents during the 1920s and 30s. By World War II, the bank numbered 200,000 species. During the 900-day Siege of Leningrad, from 1941 to 1943, the botanists caring for the collection (Vavilov had been arrested by the KGB the year before and taken to a concentration camp, where he later died) refused to eat the seeds and starved to death.

A priceless collection of fruit biodiversity, containing nearly a thousand varieties of strawberries alone, could soon be lost (courtesy of flickr user Limerick6)

The seed bank now includes hundreds of acres of field collections that contain more than 5,000 varieties of fruits, 90 percent of which can be found only at that location. There are apples, raspberries, and currants. Nearly a thousand varieties of strawberries alone. But that vast store of biodiversity could be lost in months, replaced with tracts of private homes, if developers win a court case this week.

Last December, the Russian Ministry of Economic Development sanctioned the transfer of part of the land occupied by the Pavlovsk Experimental Station, which houses the fruit collection, to a real estate development fund “on the grounds that the fields are allegedly not economically viable and are hampering the economic development of the region,” reports the St. Petersburg Times. New houses have more worth than fields devoted to science in this calculation.

“This casual decision to destroy Pavlovsk Station would forever tarnish a cause that generations of Russian plant scientists have lived and, quite literally died to protect,” said Cary Fowler of the Global Crop Diversity Trust, the organization that c0-manages the Svalbard Global Seed Vault, a.k.a. the “doomsday vault.”

The fate of the Pavlovsk collection will be decided in court—the first hearing is on Wednesday. (UPDATE: The court rejected the appeal from the Pavlovsk Station to halt the takeover, according to ScienceInsider. The first plot could be auctioned off as early as September 23.) Real estate developers have argued that since the collection is “priceless,” it has no monetary value and, in addition, that the collection doesn’t officially exist because it was never registered. Scientists disagree. Strawberry breeder Jim Hancock of Michigan State University, for example, told the Independent that the loss of the collection would be a “major tragedy” as it houses many strawberry varieties that are particularly hardy and disease-resistant.

If the experimental station loses the land on which the collection resides, it will likely be lost forever. Bulldozers could arrive in just three or four months, not enough time to move thousands of trees and other plants. Collection and quarantine regulations would prevent the plants from being sent to other countries quickly. Saving the seeds alone is not a viable option, either, as many would not survive the freezing process and, thus, it would be impossible to save them in the Svalbard Vault.

Collections like these are important not only for research. They are a way of protecting ourselves from plant diseases, natural disasters, wars or anything else that might wipe out the plant species that we depend on for food, fuel, clothing, etc. Russia is a big place. Can’t they build homes somewhere else?

How could I resist a book with the title Wicked Plants: The Weed That Killed Lincoln’s Mother & Other Botanical Atrocities? This small, elegant volume by Amy Stewart packs in a ton of information on plants that have been used to murder or to intoxicate, some that can inflict pain or cause hallucinations, and others that are “badly behaved” or are just illegal.

Wicked Plants, by Amy Stewart

The main entries for individual plants include common names, habitat and descriptions as well as stories from history. In the henbane entry, for example, Stewart mentions that the vegetable had been added to beer in the Middle Ages to enhance the intoxicating effects of the brew and that it was in part to eliminate it (and other “suspicious” ingredients) from beer that the Bavarian Purity Law was passed in 1516.

Interspersed are sections that group several plants (and in one, fungi) with similar effects, such as “Stop and Smell the Ragweed.” This entry particularly struck me, as we are deep into allergy season. There are several common garden trees and plants that could be the culprits in our suffering. The mulberry, for one, sheds billions of pollen grains. And it turns out that while Bermuda grass may be popular in the South, it is also one of the most allergenic of the grasses.

There are surprises throughout the book. Many familiar plants have hidden dark sides. My favorite flowers, tulips, produce an irritating sap—a reminder to wear my garden gloves when planting bulbs. And while there are the expected murder stories, more worrisome are the numbers of people who have died eating plants that they didn’t recognize or misidentified or simply didn’t think could be dangerous. Children and pets are, sadly, the most common victims. This is a reminder to not experiment with unknown vegetation, ever.

My one criticism is that the book lacks an index, which makes it difficult to find any specific plant, especially those that have entries only within groups. Overall, though, it is a fascinating read and a must-have for botanists and budding mystery writers.

Oh, and what was the weed that killed Lincoln’s mother? Well, that was white snakeroot (Eupatorium rugosum), which when eaten by cattle, poisons the milk and causes milk sickness. Symptoms include weakness, vomiting, tremors and delirium. Nancy Hanks Lincoln, her aunt and uncle and several other townspeople succumbed to the disease in 1818.