Quick facts

Common names: osier, common osier, basket willow

Scientific name: Salix viminalis

Family: Salicaceae

Origin: non-native

Common osier is a deciduous broadleaf tree. Mature trees grow to 7m. The bark is greyish-brown with vertical cracks. Twigs are smooth and yellow-green.

Look out for: the edges of the very narrow leaves which often appear to be rolled inwards. Catkins appear before the leaves.

Identified in winter by: the green, sparsely hairy, narrow buds which are pressed close to the twig.

What does osier willow look like?

Osier willow leaves against blue sky

Credit: Florapix / Alamy Stock Photo

Leaves

The leaves are very long and thin (20cm by 1cm), glossy and dark green with a felt-like covering of silvery hairs beneath.

Osier willow catkin close-up

Credit: Nature Photographers Ltd / WTML

Flowers

The osier is dioecious, meaning male and female flowers are found on separate plants. Its flowers are greenish catkins which appear in late winter to early spring before the leaves. Male catkins are yellow.

Osier willow female catkins releasing seeds

Credit: Nick Upton / naturepl.com

Fruits

Once pollinated, the greenish female catkins develop fruit capsules, which split open when mature to release tiny seeds.

Not to be confused with:

Other willow species which all freely hybridise.

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Where to find osier willow

Common osier is native to Europe and western Asia and thought to have been introduced to the UK in ancient times. It is often found growing in wet or damp areas, such as near rivers and streams.

Value to wildlife

Caterpillars of a number of moth species feed on the foliage, including the lackey, herald and red-tipped clearwing. The catkins provide an important source of early nectar and pollen for bees and other insects, and the branches make good nesting and roosting sites for birds.

Mythology and symbolism

There is a local custom in Chediston, Suffolk, known as a 'willow stripping' ceremony. On the night of the full moon in May, a person is dressed in willow strippings, dances around and is then thrown into the local pond.

Osier willow living sculpture in Queen Elizabeth Olympic Park

Credit: Katharine Rose / Alamy Stock Photo

Uses of osier willow

Osier withies (strong, flexible willow stems) are traditionally used for basket making and weaving, and are popular for willow screens and sculptures. Osier, like all willows, is also grown for its ability to absorb heavy metals, and is often planted to 'clean up' contaminated waste ground.

Threats and conservation

Osier may be susceptible to watermark disease caused by the bacterium Brenneria salicis. Over time, this leads to affected branches dying back and red leaves developing in the crown. If left untreated, the tree can die.

Did you know?

More than 60 different kinds of osier hybrids and cultivated varieties are grown in Britain for the basket-making industry.