River Willow
Salix fluviatilis
Family: Salicaceae
What it is like
Salix fluviatilis is a deciduous Tree growing to 7 m (23ft). See above for USDA hardiness. It is hardy to UK zone 3 and is not frost tender. It is in flower in May, and the seeds ripen in June. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Bees. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid and neutral soils. It cannot grow in the shade. It prefers moist or wet soil.
Height (m): 7
Where it is found
Forms extensive thickets and rapidly colonizes sandbars along lowland ponds, lakes and streams in moist sand or gravel overladen with silt.
Western N. America - Washington and Oregon.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 2
The bark has been used in the treatment of certain fevers. The fresh bark of all members of this genus contains salicin, which probably decomposes into salicylic acid (closely related to aspirin) in the human body. This is used as an anodyne and febrifuge.
Anodyne: Relieves pain, it is milder than an analgesic.
Febrifuge: Reduces fevers.
Other
Rating: 3
The peeled stems have been used in basket making. The inner bark can be twisted and made into a string. This plant rapidly colonizes sandbanks and wet areas near streams, lakes etc. It is therefore an extremely useful species for stabilizing banks, its network of roots holding the soil securely. It can also be used as a pioneer species to prepare the way for mature woodland. It provides good conditions for other trees to establish and is eventually out-competed by them. Dynamic accumulator.
Basketry: Plant used in making baskets and other items such as chairs. Includes plants that are only used as an ornamental addition.
Pioneer: Plants, usually trees and shrubs, that can be used to reforest land.
Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.
String: Plants that can be used for string or can be easily made into a string. See also Fibre. Plants for ropes may be included.
Dynamic accumulator: Plants that gather minerals or nutrients from the soil and store them in a more bioavailable form and in high concentration in their tissues. Used as fertilizer or to improve mulch.
How it is grown
We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors in most parts of this country. It is a fast-growing but short-lived species in the wild. The following notes are based on the general needs of the genus. Succeeds in most soils, including wet, ill-drained or intermittently flooded soils, but prefers a damp, heavy soil in a sunny position. Rarely thrives on chalk. Hybridizes freely with other members of this genus. Although the flowers are produced in catkins early in the year, they are pollinated by bees and other insects rather than by the wind. Plants in this genus are notably susceptible to honey fungus. Dioecious. Male and female plants must be grown if seed is required.
Propagating it: Seed - must be surface sown as soon as it is ripe in late spring. It has a very short viability, perhaps as little as a few days. Cuttings of mature wood of the current year's growth, November to February in a sheltered outdoor bed or planted straight into their permanent position and given a good weed-suppressing mulch. Very easy. Plant into their permanent positions in the autumn. Cuttings of half-ripe wood, June to August in a frame. Very easy.
Best place to grow: Woodland Garden Canopy; Secondary;
Habit: Tree
Hardiness: 3-7
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Moist, wet
Things to keep in mind
Its other names
Local names
Synonyms
S. melanopsis. Nutt.