Fig. 5.

Hydrodynamics target dispersal benefits to cooperating spores, and penalize spores that delay their ejection. (A) Self-organized ejection produces a sheet of spores that wraps up into a jet several centimeters above the fruiting body (figure shows the simulated vorticity [colors] and spore locations on a vertical slice of the jet: puffing starts from the right end of the apothecium). (B) The spore jet entrains a thin layer of air, whose simulated velocity profile (colors; profiles evaluated at different time points at height z = 0.2v_sτ) match our asymptotic theory (SI Appendix, black curve). (C) Cheating spores that eject behind the advancing sheet are entrained only if delayed by less than δ_j(z_s)/v_w (≈50 ms). Gray scale shows the vertical position of all cooperating spores in time, blue curve the trajectory of a single spore, green curves, the change in trajectory due to delaying ejection by less than 50 ms and red curves reduced ranges from longer delays. (D) Decrease in average spore range for cheating spores at v_s = 2 m·s^-1 (blue—SI Appendix: simulation C2) and 4 m·s^-1 (orange—SI Appendix: simulation C4). Arrows show the predicted width of the entrained air layer.