samara (fruit)

{{Short description|Non-opening dry fruit with a flattened wing}}

{{other uses|Samara (disambiguation)}}

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File:Combretum zeyheri MS2011ZA425.jpg]]

A samara ({{IPAc-en|s|ə|ˈ|m|ɑːr|ə}}, {{small|UK also:}} {{IPAc-en|ˈ|s|æ|m|ər|-}}){{cite encyclopedia | encyclopedia=Oxford English Dictionary online edition |title=samara |url=http://www.oed.com/view/Entry/170334 |access-date=30 July 2018 |publisher=Oxford University Press}} is a winged achene,{{Cite book |last=Gray |first=Asa |url=http://archive.org/details/botanyforyoungpe00gray_3 |title=Botany for young people and common subjects : how plants grow : a simple introduction to structural botany : with popular flora, or an arrangement and description of common plants, both wild and cultivated : illustrated by 500 wood engravings |date=1875 |publisher=New York : Ivison, Blakeman, Taylor |others=Fisher - University of Toronto |pages=79}} 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 further away from the tree than regular seeds would go,{{Cite book|url=https://books.google.com/books?id=4LKBcxNzHZAC|title=Trees of Pennsylvania and the Northeast|last=Fergus|first=Charles|date=2002-01-01|publisher=Stackpole Books|isbn=9780811720922|language=en}} 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).{{Cite book|url=https://books.google.com/books?id=zj395mz_GYkC|title=Nature's Flyers: Birds, Insects, and the Biomechanics of Flight|last=Alexander|first=David E.|last2=Vogel|first2=Steven|date=2004-10-13|publisher=JHU Press|isbn=9780801880599|language=en}}

There are also single-wing samara such as mahogany (genus Swietenia) which have a shape that enables fluttering.

Some species that normally produce paired samaras, such as Acer pseudoplatanus, can also produce them in groups of three or four.{{Cite book|url=https://archive.org/details/plantbiomechanic0000nikl|url-access=registration|title=Plant Biomechanics: An Engineering Approach to Plant Form and Function|last=Niklas|first=Karl J.|date=1992-08-01|publisher=University of Chicago Press|isbn=9780226586304|language=en}}

File:TripleSycamoreSamara.png|Unusual group of three samaras of sycamore maple (Acer pseudoplatanus. Normally, they are in pairs.)

File:Starr_040601-0006_Fraxinus_uhdei.jpg|Seeds of the tropical ash (Fraxinus uhdei)

File:Ptelea_trifoliata_20050606_635_part.jpg|The hoptree (Ptelea trifoliata)

File:Ulmus-pumila-samaras.jpg|The Siberian elm (Ulmus pumila)