Examples of Aerodynamic Seeds in Nature

Aerodynamic seeds exist in nature. Several genus of trees have features on seeds that make them aerodynamic for the purposes of distribution via air currents and also to help orient the radicle on the seed in a downward position. The radicle is the "point" on the seed where the root emerges upon germination, and studies have shown that when the radicle is oriented down (or not up), sprout survival rates are dramatically improved [1,2].

In many cases the shape of the seed has aerodynamic properties itself.  The attachment of a thin "sail" or "wing" which causes drag unless it is pointed upwards is also common.  In some cases this attachment is brittle and can be dislodged during handling, sorting, or processing of seeds (e.g., as with Grand Fir). In other cases this attachment is firmly affixed to the seedcoat (e.g., Longleaf Pine).  

Near universally, the aerodynamic properties of seeds appear to orient the radicle in a downward position during descent through the atmosphere in order to improve germination and sprout mortality rates.

Douglas Fir (Pseudotsuga menziesii)

Grand Fir (Abies grandis)

Jeffrey Pine (Pinus jeffreyi)

Ponderosa Pine (Pinus ponderosa)

Balsam Fir (Abies balsamea)

Chinese Red Pine (Pinus tabulaeformis)

Japanese Black Pine (Pinus thunbergii)

Japanese Red Pine (Pinus densiflora)

Longleaf Pine (Pinus palustris)

Slash Pine (Pinus elliottii)

Western Red Cedar (Thuja plicata)

We hope you enjoyed this gallery of Aerodynamic Seeds in Nature

brought to you by Aeroseed^TM.

References:

1. Paliwal, D. P., et al., Effect of sowing orientations on the germination of pine seeds, Current Science, 55:415-419 (1986).

2. Masilamani, P., et al., Influence of seed orientation and depth of sowing on germination and virour of Anjan (Hardwickia binata Roxb), Tropical Agricultural Research and Extension, 2(1):76-78 (1999).

Aeroseed^TM is a trademark of the Stable Isotope Foundation LLC.