To disperse effectively the explosively launched spores of ascomycete fungi must eject through a thin layer of still air surrounding the fruiting body and reach air flows that can take the spores away from the parent fungus. Spores are very small and therefore experience enormous fluid drag. We use a phylogeny of over 110 ascomycete species to compare optimal and real spore shapes and find that spores are shaped to remain within 1 % of the drag minimum. A predicted launch speed is confirmed by high-speed imaging of ejection in Neurospora tetrasperma. The optimal drag shapes themselves exhibit a surprising feature: they are very nearly fore-aft symmetric, despite the fact that the flow field around them is very asymmetric. We use this observation as a basis for constructing a surprisingly accurate linear approximation to steady flows of the Navier Stokes equations that works at least up to Reynolds number of order 100.