Move over, Venus flytrap. Now, there's something faster.
Using a high-speed camera, researchers have documented what may be the quickest-acting plant ever seen: the bunchberry dogwood slinging pollen into the air.
Bunchberry dogwood carpets forest floors in Canada and northern parts of the United States.
|Robert H. Mohlenbrock. USDA-NRCS PLANTS Database/USDA NRCS. 1995. Northeast wetland flora: Field office guide to plant species. Northeast National Technical Center, Chester, PA.|
A bunchberry dogwood (Cornus canadensis) has flowers that look like those of the flowering dogwood tree, but the plant itself stands only about knee high. Its tiny flowers, measuring just a few millimeters across, are cradled in clusters of four white leaflets that many people mistake for petals.
Williams College biologist Joan Edwards was inspired to study how the plant releases pollen by one of her students. While examining the flowers, the student had noticed that something suddenly "poofed." Edwards wanted to find out what was going on.
To investigate the phenomenon, she and her coworkers used a video camera that takes 1,000 pictures every second. But the images came out blurry because the camera was too slow to capture what was happening.
Next, the scientists used a superfast camera that shoots 10,000 frames per second. This time, the film showed exactly what happens when a bunchberry dogwood goes poof.
Bunchberry dogwood buds open in less than half a millisecond and fling pollen upward. That's the fastest plant motion on record. The scale bar on the left is 0.04 inch (1 millimeter).
|D. Whitaker, M. Laskowski, A. Acosta, J. Edwards|
The tiny flower's petals are highly elastic. The petals flip backward and release springy filaments. The filaments act like miniature versions of an ancient catapult known as a trebuchet. They snap upward, causing pollen to spray from containers hinged to the filaments.
The mechanism unfolds so fast that the pollen experiences 800 times more gravitational force than an astronaut does in a space shuttle during launch. No known plant, not even the snapping Venus flytrap, comes close to that kind of speed.—E. Sohn
Milius, Susan. 2005. World's fastest plant explodes with pollen.  Science News 167(June 11):381. Available at http://www.sciencenews.org/articles/20050611/note12.asp  .
Videos showing a bunchberry dogwood flower shooting out pollen can be seen at www.oberlin.edu/news-info/05may/expflower.html  (Oberlin College).
Learn more about the bunchberry dogwood at plants.usda.gov/cgi_bin/topics.cgi?
earl=plant_profile.cgi&symbol=COCA13  (U.S. Department of Agriculture).
Sohn, Emily. 2005. How a Venus flytrap snaps shut.  Science News for Kids (Feb. 2). Available at http://www.sciencenewsforkids.org/articles/20050202/Note3.asp  .