In this paper, my co-authors and I discuss our findings that the Hura crepitans seeds (which disperse in a spectacular explosion) fly with backspin, as opposed to the previously assumed topspin. And it turns out that flying with backspin actually helps seeds reduce the drag force acting on them, which means that they can fly further and grow in new habitats more effectively! Flying with backspin has also been observed in another species (where the behaviour evolved independently), and we conclude that comparing the dispersal mechanisms across two plant families may be a good direction for research aiming to understand the adaptive significance of this behaviour.
The Ceiba speciosa diaspore looks like a floating piece of white cotton candy with a hard seed in the middle. The diaspore can float through the air for long distances because it is able to generate signifantly more drag than a solid sphere, and this thesis tries to unpack how that happens. Comparing the diaspore to other drag enhancing diaspores revealed that they might all be generating drag using similar mechanisms. Ultimately, understanding said mechanisms will require imaging the flow of air in the diaspore's wake, and thus the thesis also describes improvements made to the wind tunnel and flow imaging setup in our lab.