Flowery words
Beauty is said to be in the eye of the beholder, but a recent study demonstrates that for some, the true appeal of a flower may lie in what can be felt rather than seen.
Many gardens that are designed to attract bees are noted for the wide variety of flowering plants, including daisies, zinnias and lavender, rich in nectar and pollen that can be converted into honey. In a study from the journal Functional Ecology published May 28, British scientists showed that another reason these plants appeal to bees can be found on the surface of the petals.
“Many of our common garden flowers have beautiful conical cells if you look closely,” said study senior author Beverley Glover, a plant scientist at the University of Cambridge in the United Kingdom, in a statement. “Roses have rounded conical petal cells while petunias have really long cells, giving petunia flowers an almost velvety appearance, particularly visible in the dark-colored varieties.”
In a series of experiments, Glover and her colleagues tried to simulate a windy day to see if they could shake bees off several petunia plants, some of which had the conical petal cells that allow the bees to hang grip the flowers, and others which had differently shaped petal cells. They found that the conical shape of the tiny cells on flower petals allows the insects to firmly grip the plant to harvest the nutrients they need even under adverse conditions. They suggested that the usefulness of the conical cells to bees, and potentially other pollinators, might help explain why so many flowering plants have this type of cells.
“Nobody knew what these cells were for, and now we have a good answer that works for pretty much all flowers,” Glover added. “When you put yourself into the bee’s shoes you find hidden features of flowers can be crucial to foraging success.”
For a garden to attract attention year-round from humans and pollinators, it would need to have a wide variety of plants that can be differentiated not just by size and color, but by growing season. In the May 25 issue of the journal Science, an international team of scientists described finding a “switch” that can turn on a plant’s flowering process.
In recent years, there have been reports around the world of plants flowering several months ahead of schedule, responding to temperature shifts that have led in some cases to T-shirt weather for places that should be still be under snow during that time of the year.
An example of how these changing conditions have affected ecosystems can be found in the same issue of Science as a British research team tracked a butterfly that has moved several kilometers north of its previous habitat in the past 30 years and changed its main food source.
The butterfly’s new food of choice turns out to be a plant that had previously only been available to the insect during warm summers in the south of England; with warmer temperatures throughout the country, the plant has become more widely available, allowing the butterfly to extend its habitat.
Returning to the plant study, work done previously has shown that a plant relies on both the data on its surroundings as gathered through sensors and its internal clock to determine whether or not there is enough sunlight available on a daily basis to flip a switch and start flowering.
Understanding why plants can be tricked into flowering earlier than expected, could be useful not just for gardeners but for farmers and crop breeders. “If we can regulate the timing of flowering, we might be able to increase crop yield by accelerating or delaying this,” said the study’s senior author, Taikato Imaizumi of the University of Washington in the United States, in a statement. “Knowing the mechanism gives us the tools to manipulate this.”
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