Dandelion seeds use a specialized flight apparatus called a pappus, consisting of 100–200 fine filaments, to achieve long-distance wind dispersal over several to several dozen kilometers. Unlike membrane-like parachutes, the pappus has a highly porous structure that generates a vortex ring in its wake. However, it is unclear why plumed seeds chose a bristly pappus over a membrane that resembles wings and is known to increase lift during passive flight. In the present study, scanning stereoscopic PIV measurements were carried out in the wake of the pappus to investigate the three-dimensional wake structure related to its aerodynamic performance. The flow directed toward the center of the pappus was observed between adjacent filaments. This flow contributed to the stabilization of the vortex ring in the wake.
URAKATA et al. (2025) studied this question.