- You are here:
- Dichotomous Key
- Salicaceae
- Salix
- Salix key for carpellate reproductive material
- Salix alba
Salix alba — white willow
Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.
Facts
White willow is so-named for its long, tapering leaves which are downy white on the undersides. Its bark is yellow and ridged. The branchlets are brittle and break easily, sometimes leaving a litter of fallen twigs on the ground beneath the crown. Weeping willow is a hybrid between this species and Peking willow (Salix babylonica). Golden weeping willow is another cultivar of this species that can grow very large and produce leaves that turn golden in the fall. White willow is tolerant of wet soils.
Habitat
Anthropogenic (man-made or disturbed habitats), floodplain (river or stream floodplains), meadows and fields, shores of rivers or lakes, wetland margins (edges of wetlands)
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Growth form
- the plant is a tree
- Leaf type
- the leaf blade is simple (lobed or unlobed but not separated into leaflets)
- Leaves per node
- there is one leaf per node along the stem
- Leaf blade edges
- the edge of the leaf blade has teeth
- Leaf duration
- the leaves drop off in winter (or they wither but persist on the plant)
- armature on plant
- the plant does not have spines, prickles, or thorns
- Leaf blade length
- 40–120 mm
- Leaf blade width
- 10–30 mm
- Leaf stalk
- the leaves have leaf stalks
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Bark texture
- the bark of an adult plant is ridged or plated
- Twig winter color
-
- brown
- gray
- green
- red
- yellow
- Bud scale number
- there is one scale on the winter bud, and it covers the scale like a cap
-
Buds or leaf scars
- Bud scale number
- there is one scale on the winter bud, and it covers the scale like a cap
- Bud scar shape (Fraxinus)
- NA
- Collateral buds
- there are no collateral buds on the sides of the branches
- Leaf scar arrangement
- there is one leaf scar per node on the stem or twig
- Superposed buds
- there are no superposed buds on the branch
- Winter bud distribution
- the winter buds are distributed fairly evenly along the twig
- Winter bud scale hairs
- the winter bud scales are hairy
- Winter bud scales
- the winter bud is perulate (partially or completely covered with one or more scales)
- Winter bud shape
-
- the winter buds are ellipsoid (elliptical in three dimensions)
- the winter buds are ovoid (egg-shaped)
- Winter bud stalks
- the winter buds have no stalks
-
Flowers
- Anther color
-
- the anthers show no hint of a pink, reddish or purplish tint
- there is a noticeable pink, reddish or purplish tint to the anthers
- Carpels fused
- the carpels are fused to one another
- Enlarged sterile flowers
- there are no enlarged sterile flowers on the plant
- Flower petal color
- NA
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Hairs on ovary (Amelanchier)
- NA
- Hypanthium present
- the flower does not have a hypanthium
- Inflorescence position
- the inflorescences grow on the twigs
- Inflorescence type
- the inflorescence is an ament (catkin; slender, usually pendulous inflorescence with crowded unisexual flowers)
- Number of pistils
- 1
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Petal and sepal arrangement
- the flower lacks sepals and petals
- Petal appearance
- NA
- Petal fusion
- NA
- Sepal appearance
- NA
- Sepal cilia (Ilex)
- NA
- Sepal tip glands
- NA
- Sepals fused only to sepals
- NA
- Stamen number
- 1 or 2
- Stamen position relative to petals
- NA
- Stamens fused
- the stamens are not fused to one another
-
Fruits or seeds
- Berry color
- NA
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit type (specific)
- the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
- Nut with spines (Fagaceae)
- NA
- Wings on fruit
- there are no wings on the fruit
-
Glands or sap
- Sap color
- the sap is clear and watery
- Stalked glands on fruit (Rosa)
- NA
-
Growth form
- Growth form
- the plant is a tree
-
Leaves
- Hairs on underside of leaf blade
-
- the underside of the leaf has hairs on it
- the underside of the leaf has no hairs
- Hairs on upper side of leaf blade
-
- the upper side of the leaf is fuzzy or hairy
- the upper side of the leaf is not hairy, or has very few hairs
- Leaf blade base shape
- the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
- Leaf blade base symmetry
- the leaf blade base is symmetrical
- Leaf blade bloom
- there is a noticeable powdery or waxy bloom on the underside of the leaf
- Leaf blade edges
- the edge of the leaf blade has teeth
- Leaf blade edges (Acer)
- NA
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- the hairs on the leaf blade are different from the choices given
- Leaf blade length
- 40–120 mm
- Leaf blade scales
- there are no scales on the leaf blades
- Leaf blade shape
-
- the leaf blade is elliptic (widest near the middle and tapering at both ends)
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- Leaf blade texture
-
- the leaf blade is coriaceous (has a firm, leathery texture)
- the leaf blade is herbaceous (has a leafy texture)
- Leaf blade translucent dots
- there are no translucent dots on the leaf blade
- Leaf blade vein pattern
- the main veins of the leaf blade are pinnate (the secondary veins branch off at intervals from the main central vein) and non-arcuate (not arched towards the leaf tip)
- Leaf blade veins
- the leaf blade has one main vein running from the base toward the tip
- Leaf blade width
- 10–30 mm
- Leaf duration
- the leaves drop off in winter (or they wither but persist on the plant)
- Leaf form
- the plant is broad-leaved (with broadly flattened leaf blades)
- Leaf lobe tips (Quercus)
- NA
- Leaf midrib glands
- the midrib of the leaf blade lacks glands on the upper surface
- Leaf stalk
- the leaves have leaf stalks
- Leaf stalk attachment to leaf
- the petiole attaches at the basal margin of the leaf blade
- Leaf stalk nectaries
- the leaf stalk has nectaries on it
- Leaf stalk shape
- the leaf stalk is not flattened
- Leaf teeth
-
- the leaf blade margin has teeth, which themselves have smaller teeth on them
- the leaf blade margin is serrulate (with forward-pointing) or denticulate (with outward-pointing) with tiny teeth
- Leaf teeth hairs (Carya)
- NA
- Leaf type
- the leaf blade is simple (lobed or unlobed but not separated into leaflets)
- Leaves per node
- there is one leaf per node along the stem
- Specific leaf type
- the leaves are simple (lobed or unlobed but not separated into leaflets
- Stipules
- there are no stipules on the plant, or they fall off as the leaf expands
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- edges of wetlands
- man-made or disturbed habitats
- meadows or fields
- river or stream floodplains
- shores of rivers or lakes
-
Scent
- Plant odor
- the plant does not have much of an odor, or it has an unpleasant or repellant odor
-
Stem, shoot, branch
- Aerial roots
- the plant has no aerial roots
- Bark texture
- the bark of an adult plant is ridged or plated
- Branch brittleness (willows only)
- the branches are brittle, and break easily
- Branch cross-section
- the branch is circular in cross-section, or it has five or more sides, so that there are no sharp angles
- First-year cane (Rubus)
- NA
- Lenticels on twigs
- there are no lenticels on the twigs, or they are very hard to see
- Pith shape
- the outline of the pith in a twig is roughly round
- Pith type
- the pith inside the twig is solid, completely filled with spongy tissue
- Short shoots
- there are no peg- or knob-like shoots present
- Twig bloom
- there is no bloom on the twig
- Twig hairs
- the twigs have hairs, but the hairs do not have glands
- Twig papillae (Vaccinium species only)
- NA
- Twig scales
- there are no scales on the twig surface
- Twig winter color
-
- brown
- gray
- green
- red
- yellow
- Wings on branch
- the branch does not have wings on it
- armature on plant
- the plant does not have spines, prickles, or thorns
Wetland status
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- unranked (S-rank: SNR)
var. alba
- Massachusetts
- unranked (S-rank: SNR)
var. caerulea
- Massachusetts
- unranked (S-rank: SNR)
var. vitellina
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
1. Salix alba L. E
white willow. 1a. Salix alba L. ssp. caerulea (Sm.) Rechinger f.; S. alba L. var. caerulea (Sm.) Sm.; S. alba L. var. calva G.F.W. Mey.; S. alba L. ssp. vitellina (L.) Arcang.; S. alba var. vitellina (L.) Stokes; S. vitellina L.; • CT, MA, ME, NH, RI, VT. Riparian forests, river banks, roadsides, field edges, wetland margins, near dwellings. There are four forms of this willow that occur in New England. The “vitellina” form has bright yellow to bright orange-yellow winter branchlets and floral bracts commonly 3–3.5 mm long. The “caerulea” form has brown to green-brown winter branchlets, floral bracts 2.5–3 mm long, mature leaf blades often longer than 10 cm, 1.5–2 cm wide, and usually becomes glabrate on the abaxial surface. The “alba” form has branchlets and floral bracts similar to the preceeding, but has leaf blades 5–10 (–12) cm long, 0.5–1.5 cm wide, and often remain long-sericeous on the abaxial surface. A fourth form, which may be referable to “micans” of Europe, is similar to the “alba” form but has the leaf blades densely and persistently long-sericeous with white hairs. These forms are regarded as valid infraspecific taxa in Europe (where they occur as natives; e.g., Meikle 1984) but are treated as cultivars by some North American authors (e.g., Argus 1986). Until the appropriate rank to treat these taxa can be determined, they are here recognized informally.
1×16. Salix alba × Salix lucida → Salix ×jesupii Fern. has been incorrectly called S. ×ehrhartiana by various New England authors (but that hybrid has S. alba and S. pentandra as parents and is not known to occur in New England). Salix ×jesupii is known from CT, MA, NH, VT. This hybrid is a tall shrub or small tree 4–8 m tall with abaxially glaucous leaf blades (rather than green and not glaucous in S. lucida) that show a mixture of white and red-brown hairs. The blades are mostly 2.8–4.8 times as long as wide (vs. mostly 4.2–7.3 times in S. alba). The staminate flowers have 3 or 4 stamens (rather than 2 in S. alba).
1×Salix babylonica L. Salix ×sepulcralis Semonkai is primarily responsible for reports of S. babylonica in New England, which is an Asian species that is not hardy in the northeastern United States. Salix ×sepulcralis is known from CT, MA, ME, NH, VT. It is recognized by its conspicuously pendulous branches and branchlets and gold-yellow (or less frequently green-yellow) branchlets. It is very similar to another S. babylonica hybrid in New England called S. ×pendulina; however, that nothotaxon has green-brown (or less frequently yellow-brown, gray-brown, or red-brown) branchlets.
1×Salix euxina I.V. Belyaeva. Salix ×fragilis L. [Fig. 887] is a frequent willow hybrid known from CT, MA, ME, NH, RI, VT. It resembles S. alba but has sparsely pubescent to glabrous leaf blades, coarser, sometimes slightly irregular, teeth, and larger, asymmetrical stipules. From S. euxina it differs in its amphistomatous, usually abaxially sparsely pubescent leaves and relatively loosely flowered aments (leaves both glabrous and hypostomatous and aments relatively densely flowered in S. euxina). This hybrid, which is fully naturalized in riparian and lacustrine floodplains, is responsible for reports of Salix euxina in New England (note: S. euxina was formerly referred to as S. fragilis, and this hybrid was formerly referred to as S. ×rubens Schrank; Belyaeva 2009). The nothovarietal epithet “ basfordiana” applies to our material; however, the appropriate combination has not yet been made.
Native to North America?
No
Sometimes confused with
- Salix nigra:
- leaf blades green on the lower surface, with small, but evident, stipules at the base of the leaf stalk (vs. leaf blades with a whitish bloom on the lower surface, without or with minute stipules at the base of the leaf stalk).
Synonyms
- Salix alba ssp. vitellina (L.) Arcang.
- Salix vitellina L.