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Willow

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The genus Salix contains approximately 350 different species of plants. These plants are mostly deciduous trees or shrubs. Deciduous means they lose their leaves every year. You will find them mainly in cold and temperate regions. They prefer to grow in moist soils. Some species, like the dwarf willow, are very small. They stay low to the ground and spread widely.

Willow tree in spring, England
Willow tree in spring, England

Willows have unique physical features that help them survive. Their bark contains a watery sap that is rich in salicin. The wood is usually soft, tough, and pliant. They possess large, fibrous roots that are very tenacious. These roots are so strong they can sprout from aerial parts of the plant. The leaves are often elongated or oval with serrated edges. They come in many shades of green, from yellowish to bluish.

Salix silesiaca a5
Salix silesiaca a5

These plants follow a specific cycle with the seasons. In the northern hemisphere, they are among the first woody plants to grow leaves. This process, called leafout, is stimulated by air temperature. If daytime highs stay warm for a few days, the willow grows leaves. In the autumn, they drop their leaves when the days shorten. This happens when the day length reaches about ten hours and 25 minutes.

Weeping Willow by Pond
Weeping Willow by Pond

Most willows are dioecious, meaning male and female flowers grow on separate plants. These flowers appear in fuzzy clusters called catkins or aments. The male flowers are called staminate flowers. They consist of stamens that can be rose-colored or orange. The female flowers are called pistillate flowers. They contain a single ovary and many ovules. These catkins often appear in early spring before the leaves grow.

Young-catkin
Young-catkin
Salix cinerea flowers-2
Salix cinerea flowers-2

Humans have interacted with willows for thousands of years. The name Salix was used scientifically by Carl Linnaeus in 1753. The oldest willow fossils come from the early Eocene in North America. Ancient people in Egypt and Sumer used willows for medicine. The Greek physician Hippocrates wrote about willow in the fifth century BC. Some believe the name comes from a Celtic words meaning "near water."

Willow species with Honeysuckle woodbine
Willow species with Honeysuckle woodbine

Willows play a huge role in their ecosystems. Beavers use the wood to build their dams. Bees visit the flowers for nectar and pollen. Some insects, like the mourning cloak butterfly, use the leaves for food. However, they also host over one hundred species of aphids. These tiny insects feed on the plant juices. Fungi can also cause rust, which creates orange spots on the leaves.

Bourgoyen knotted willow and woodpile
Bourgoyen knotted willow and woodpile

People use willows for many different purposes. Some Native American tribes used the bark for twine. They also used the wood to start fires or build fishing weirs. In modern times, they are used for landscaping and bioenergy. Some species are even used to control erosion along watercourses. However, in Australia, some planted species are now considered invasive weeds.

Kopfweiden 1
Kopfweiden 1
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🖼️ Images & Media (10)
File:Salix silesiaca a5.jpg
Salix silesiaca a5.jpg
File:Young-catkin.jpg
Young-catkin.jpg
File:Bourgoyen knotted willow and woodpile.jpg
Bourgoyen knotted willow and woodpile.jpg
File:Kopfweiden 1.jpg
Kopfweiden 1.jpg
File:Weeping Willow by Pond.jpg
Weeping Willow by Pond.jpg
File:A Modern Cricket Bat.jpg
A Modern Cricket Bat.jpg
File:Salix cinerea flowers-2.jpg
Salix cinerea flowers-2.jpg
File:Willow tree in spring, England.JPG
Willow tree in spring, England.JPG
File:Willow species with Honeysuckle woodbine.JPG
Willow species with Honeysuckle woodbine.JPG
File:Sandworm by Marco Casagrande @ Wenduine, Belgium.jpg
Sandworm by Marco Casagrande @ Wenduine,...
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