The Spinning Rotation of Ash and Tulip Tree Samaras

Ash and tulip tree samaras rotate on their long axes as they fall, as well as spin around like maple samaras. They descend faster than would maple samaras of the same size and weight and much faster than would zanonia samaras, but they are very stable, which may explain their evolutionary success.

[1]  A. Smith,et al.  On the Motion of a Tumbling Body , 1953 .

[2]  E. H. Smith Autorotating wings: an experimental investigation , 1971, Journal of Fluid Mechanics.