Samara (fruit)

Acer circinatum 9468

Combretum zeyheri MS2011ZA425

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TripleSycamoreSamara

Starr 040601-0006 Fraxinus uhdei

Ptelea trifoliata 20050606 635 part

Ulmus-pumila-samaras

Samara is a type of fruit characterized by its winged achene, a simple dry fruit that does not open at maturity to release its single seed. The samara is most commonly associated with trees in the maple (Acer) family, but it is also found in other families such as Elm (Ulmus), Ash (Fraxinus), and Birch (Betula). This unique fruit design is nature's way of enabling seed dispersal over greater distances by wind, a process known as anemochory.

Description

A samara consists of a flattened wing of fibrous, papery tissue, which develops from the ovary wall. The seed is located at one end of the wing. In some species, the samara is shaped like a paddle, while in others it is more elongated. The shape and size of the samara can vary significantly between species, influencing how far the seed can travel from the parent tree. The lightweight and aerodynamic design of the samara allows it to glide through the air, rotating as it falls, which can carry the seed to locations far from the parent tree.

Function

The primary function of the samara is to aid in the dispersal of the tree's seeds. By catching the wind, samaras can be carried away from the dense competition beneath the parent tree, increasing the seed's chances of finding a suitable habitat for germination and growth. This dispersal strategy helps to reduce the density-dependent mortality that seeds might face if they were to fall and grow directly beneath their parent tree.

Examples

• The Maple tree is perhaps the most well-known example, with its distinctive double-winged samaras often referred to as "helicopter seeds" due to their spinning flight.
• Elm trees produce a single-winged samara that is oval or circular in shape.
• Ash trees have samaras that are paddle-shaped, with a single seed located at one end.
• Birch trees, although more commonly associated with catkin-type fruits, also produce small, winged samaras.

Ecological Importance

Samaras play a crucial role in the ecosystem. By facilitating seed dispersal, they help maintain the genetic diversity and spatial distribution of tree populations. This dispersal mechanism allows trees to colonize new areas, which can be particularly important in environments that have been disturbed by natural events or human activities. Furthermore, the seeds contained within samaras serve as a food source for various wildlife, including birds and small mammals.

Cultural Significance

In addition to their ecological role, samaras have captured human imagination and interest. Children and adults alike are often fascinated by the spinning flight of maple samaras, which can inspire curiosity about nature and plant biology. Samaras have also been studied for their potential applications in biomimicry, particularly in the design of air-borne vehicles and in understanding the physics of flight.