A samara (//, UK also: /-/) is a winged achene, a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit, and is indehiscent (not opening along a seam). The shape of a samara enables the wind to carry the seed farther away from the tree than regular seeds would go, and is thus a form of anemochory.
In some cases the seed is in the centre of the wing, as in the elms (genus Ulmus), the hoptree (Ptelea trifoliata), and the bushwillows (genus Combretum). In other cases the seed is on one side, with the wing extending to the other side, making the seed autorotate as it falls, as in the maples (genus Acer) and ash trees (genus Fraxinus).
Unusual group of three samaras of sycamore maple (Acer pseudoplatanus. Normally, they are in pairs.)
Seeds of the tropical ash (Fraxinus uhdei)
The hoptree (Ptelea trifoliata)
The Siberian elm (Ulmus pumila)
A samara is sometimes called a key and is often referred to as a wingnut, helicopter, whirlybird, whirligig, polynose, or, in the north of England, a spinning jenny. During the autumn months, they are a popular source of amusement for children (and adults) who enjoy tossing them in the air and watching them spin to the ground.
- "samara". Oxford English Dictionary online edition. Oxford University Press. Retrieved 30 July 2018.
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- Alexander, David E.; Vogel, Steven (2004-10-13). Nature's Flyers: Birds, Insects, and the Biomechanics of Flight. JHU Press. ISBN 9780801880599.
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- "Seed dispersal by wind: Gone with the wind - Woodland Trust". www.woodlandtrust.org.uk. Retrieved 2016-03-15.
- Spinning Flight : Dynamics of Frisbees, Boomerangs, Samaras and Skipping Stones, Ralph Lorenz, Copernicus New York, September 2006 ISBN 0-387-30779-6