Salix alba L., White Willow
Account Summary
Introduction, archaeophyte, deliberately planted, occasional. Eurosiberian southern-temperate, but widely naturalised.
1900; Praeger, R.Ll.; Co Fermanagh.
January to November.
Growth form and preferred habitats
A tall, graceful tree, 10-25 m tall of varying crown shape which forms a distinctive and well established feature of wet to damp, lowland, field, riverbank and roadside hedges around Upper Lough Erne and the Lisnaskea area in particular. S. alba has a more upright crown and is clothed with more attractive, silvery-white-coated foliage than S. fragilis (Crack Willow), yet it appears slightly less frequently planted than the latter in Fermanagh. Long regarded as an alien introduction in Ireland, S. alba is always planted, or originates from planted material which may have reproduced and spread to some extent along or away from original, deliberately chosen, waterside sites.
Catkins appear with the leaves in late April or early May and after insect pollination the capsules ripen in July or early August (Meikle 1984). The only critical requirements for willow establishment are damp or wet ground for seed germination and seedling growth, and full sunlight. All willows require full sunlight and they will not grow well without it, indeed, any shaded part of a plant soon dies. Otherwise, most Salix species are environmentally relatively undemanding, although S. pentandra (Bay Willow) and S. fragilis (Crack-willow) and their various forms do not perform well on calcareous soils and tend to avoid them. When planting willows, it should always be remembered that all of them age quickly and tend to become unsafe. An old willow wood always contains leaning and broken specimens, reducing the ornamental value of the stand (White 1992).
Apart from its ornamental value, S. alba was previously valued for basketry and undoubtedly one or more cultivars of it will have been planted locally for this purpose. Until basket-making declined sometime in the 1930s or earlier, some plantings of S. alba varieties would have been coppiced, or less likely in the area, pollarded at intervals to produce canes. There does not seem to be any surviving evidence of this practice locally in Fermanagh, as far as we are aware, but while willows are extremely rapid in growth they are not long-lived trees (White 1992), and we therefore feel that this absence is not significant.
Fermanagh occurrence

Despite being of more attractive appearance, S. alba appears slightly less frequently planted than S. fragliis (Crack-willow) in Fermanagh. The greatest difference in their occurrence is that White Willow is very much more localised than Crack-willow, being almost entirely concentrated around Upper Lough Erne. S. alba is recorded from a total of 57 tetrads, 10.8% of those in Fermanagh, while the comparable figure for S. fragilis is 13.6%, although the latter is much more widely scattered. Unfortunately we do not know to what extent S. alba is fully naturalised and capable of seeding itself in Fermanagh, but it does so rarely elsewhere in B & I. More local study is required.
Meikle (1984) describes three varieties that are widely planted in B & I, but we have no details of these in our survey.
Irish occurrence
The New Atlas map shows S. alba is widely distributed throughout Ireland, although there are a large number of hectads plotted with only pre-1970 records, especially in counties on or close to the western seaboard. These areas have a predominance of strongly acid, peaty soils of poor nutrient status and in coastal areas there is excessive wind exposure. Even if it were planted in the west, both these factors would limit or exclude the growth of this normally large tree species, which naturally demands reasonable substrate fertility and stability.
British occurrence
In Britain, until very recently, White Willow was another of those species, which despite a long history of widespread plantation managed to retain native status, perhaps more from tradition than through any rational scientific analysis (Stace 1997). After an examination of the status question, it is now recognised as an archaeophyte throughout B & I (Preston et al. 2002; Preston et al. 2004). S. alba is widespread and locally common in suitable lowland waterside habitats in Britain, stretching across the whole latitudinal range. It does, however, become more scarce as one travels N & W, and it appears to be declining in N & W Scotland in the same manner as occurs in W Ireland (G. Hutchinson, in: Preston et al. 2002).
European and world occurrence
Although this species is often planted, making it difficult to be certain where it is native, S. alba appears widespread in Europe, extending across middle latitudes from southern Denmark eastwards to C Asia and south to the Mediterranean region (Meikle 1984; Jalas & Suominen 1976, Map 203).
Threats
Many of the larger trees are over-mature and will soon become subject to windfall or simply die, since this is not a long-lived species.