Withy or withe is a strong flexible willow

Willow

Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

 stem that is typically used in thatching

Thatching

Thatching is the craft of building a roof with dry vegetation such as straw, water reed, sedge , rushes, or heather, layering the vegetation so as to shed water away from the inner roof. It is a very old roofing method and has been used in both tropical and temperate climates...

 and for gardening. An advantage of using this type of material is said to be a greater resistance to woodworm

Woodworm

A woodworm is not a specific species. It is the larval stage of certain woodboring beetles including:*Ambrosia beetles *Bark borer beetle / Waney edge borer *Common furniture beetle...

.

Several species and hybrid cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s of willows (often known as osiers) are grown for withy production; typical species include Salix acutifolia

Salix acutifolia

Salix acutifolia, also known as long-leaved violet willow, is a shrub in the Salicaceae family....

, Salix daphnoides, Salix × mollissima, Salix purpurea, Salix triandra

Salix triandra

Salix triandra is a species of willow native to Europe and western and central Asia, from southeastern England east to Lake Baikal, and south to Spain and the Caucasus and Alborz mountains...

, and Salix viminalis.

The term is also sometimes used to describe any type of flexible rod used in rural crafts

Rural crafts

Rural crafts refers to the traditional crafts production that is carried on, simply for everyday practical use, in the agricultural countryside. Once widespread and commonplace, the survival of some rural crafts is now in doubt....

 such as hazel

Hazel

The hazels are a genus of deciduous trees and large shrubs native to the temperate northern hemisphere. The genus is usually placed in the birch family Betulaceae, though some botanists split the hazels into a separate family Corylaceae.They have simple, rounded leaves with double-serrate margins...

 or ash.

Withies are traditionally used to mark minor tidal channels in UK harbours and estuaries. In many places they are still in use today and are often marked on navigation charts. At high tide the tops of a line of withies stuck in the mud on one or both sides of the channel will show above water to indicate where the deeper water lies. International navigation chart symbols for withies (port and starboard) are pictured.
Places such as Wythenshawe

Wythenshawe

Wythenshawe is a district in the south of the city of Manchester, England.Formerly part of the administrative county of Cheshire, in 1931 Wythenshawe was transferred to the City of Manchester, which had begun building a massive housing estate there in the 1920s to resolve the problem of its inner...

 and Withy Grove in Manchester

Manchester

Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...

 take their names from the willow woods and groves that grew there in earlier times. The Somerset Levels

Somerset Levels

The Somerset Levels, or the Somerset Levels and Moors as they are less commonly but more correctly known, is a sparsely populated coastal plain and wetland area of central Somerset, South West England, between the Quantock and Mendip Hills...

is now the only area in the UK where basket willow is grown commercially.