Willow (Family Salicaceae)

 

There are about 400 species in the Family Salicaceae including willows

and poplars. This family has always been taxonomically difficult and

continues to be. The Angiosperm Phylogeny Group recently reexamined

and reconfigured Family Salicaceae; further research can be anticipated.

 

Members of Family Salicaceae are distributed throughout the world (ex-
cepting Antarctica), but are most common in temperate climates.

 

Many species of willows are important ecologically. Willows are often

species of early succession, and they are important in the early and middle
stages of successional recovery after disturbance. Because willows grow
quickly and are so easy to propagate using stem cuttings, they are often
used to vegetate stream banks to help prevent erosion and sometimes to
re-vegetate other types of disturbed lands. In addition to reclamation,
willows are an important browse of mammals such as deer, moose, rabbits,
hares, and other species, especially during the winter when herbaceous
forage is not very available. Willows may be an important source of nectar
for bees in the early spring, a time when few other species of insect-polli-
nated plants are flowering. Willow honey may be a locally significant pro-
duct in some areas.

 

Tree-sized willows are sometimes used for lumber. The black willow is

the only species used much for this purpose in North America. Because

its wood is not very strong, it is generally used to manufacture boxes and

similar goods. However, because willow twigs are flexible, they have been

used to weave baskets and to make fences and lattices.

 

There has been research into the cultivation of tree-sized willows in planta-
tions for use as a biomass fuel. This use of willows as a source of renewable
energy may prove to be important in the future. The willow biomass can be
burned directly, or it can be chemically converted into more easily portable
liquid fuels such as alcohol or a synthetic, petroleum-like mixture.

 

Willows have long had some use in folk medicine. Many cultures are known
to have chewed willow twigs to relieve pain and fever. The original source
from which salicylic acid was extracted was the bark of the white willow
(Salix alba) of Europe. This chemical is used to manufacture acetylsalicylic
acid (commonly known as aspirin), probably the world's most important
analgesic, used for treating pain, fever, and inflammation.

 

Some species of willows can be "straggly" and difficult to control, others
are deemed as haviing " good aesthetics" and are utilized in horticulture
and for ornamentation. One of the best known species for this purpose is
the weeping willow (Salix babylonica), a beautiful, pendulous tree that
has been widely introduced to North America as an ornamental tree. Other
non- native species that are commonly used in horticulture include the
crack willow (Salix fragilis) of Eurasia and the white willow (Salix alba)
and basket willow (Salix viminalis) of Europe. Some of these species have
escaped from cultivation and have become locally invasive in natural habi-
tats. Some wild willows also have pleasant aesthetics. Most famous in this
sense are the several species known as "pussy willows," especially the
pussy willow (Salix discolor).

 

 

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