122-3 Sunday, Jan. 7 10:30 - 10:45 Dispersal of seeds from splash-cup plants PEPPER, RE; University of Puget Sound email@example.com
Splash cup plants disperse their seeds with the help of raindrops. The seeds sit in a small conical cup (a few millimeters across) and are ejected upon drop impact. The seeds are ejected at velocities up to five times the impact speed of the raindrop, and are dispersed up to 1 m away from the parent plant, which is only a few centimeters high. Previous work by Amador et al. investigating the mechanism of this remarkable dispersal predicted an optimum cup opening angle of around 30°, which matched reasonably well with both the opening angle of splash cup plant species found in nature and experiments measuring dispersal distance performed with 3D-printed splash cup models. Those experiments were done with off-center drop impacts on initially empty cups with no seeds. We discuss similar experiments for cups that are not initially empty, but rather contain seed mimics, water, or both seeds and water. For some of these realistic initial states results are strikingly different from empty cups. Connections to theory will also be discussed.