Summary 1.The flower of Brassica napus L. appears to be typically zoophilous (suited to animal pollination) because of its visually attractive petals, robust stigma and nectaries. Pollination by wind is feasible, however, and its likely effectiveness is not immediately foreseeable because of the complexity of interactions between objects and windborne particles. 2. Computational fluid dynamics (CFD) and wind-tunnel experiments were used to investigate the aerodynamic interactions between the flower and a windborne suspension of its pollen. 3. The flower's petals handicapped wind pollination by reducing the target efficiency of the upwind-facing stigma. For downwind-facing flowers, pollen reception was negligible. 4. Several aspects of the plant's architecture (floral structure, pollen cohesiveness, inflorescence structure) are uncompromisingly zoophilous. Estimates of the amount of wind pollination suggest that it is unlikely to be important for the long-distance dispersal of B. napus genes such as those from genetically modified varieties. 5. This study illustrates how CFD may become a powerful tool in future analyses of wind pollination.

In many pine species (Family Pinaceae), ovulate cones structurally resemble a turbine, which has been widely interpreted as an adaptation for improving pollination by producing complex aerodynamic effects. We tested the turbine interpretation by quantifying patterns of pollen accumulation on ovulate cones in a wind tunnel and by using simulation models based on computational fluid dynamics. We used computer-aided design and computed tomography to create computational fluid dynamics model cones. We studied three species: Pinus radiata, Pinus sylvestris, and Cedrus libani. Irrespective of the approach or species studied, we found no evidence that turbine-like aerodynamics made a significant contribution to pollen accumulation, which instead occurred primarily by simple impaction. Consequently, we suggest alternative adaptive interpretations for the structure of ovulate cones.aerodynamics ͉ computational fluid dynamics ͉ computed tomography ͉ wind pollination