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- Ulmus rubra
Ulmus rubra — slippery elm
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Facts
A denizen of moist, rich habitats such as floodplains (and occasionally limestone uplands), slippery elm gets its common name from the mucilaginous substance produced by its inner bark. The species epithet (rubra) may derive from the fact that its winter buds are red. Look for small hairs (cilia) along the edges of the leaves. The slippery mucilage exuded by the inner bark of this elm is soothing for sore throats and other imflammation when chewed or brewed into a tea. Slippery elm is not widely planted because it is less statuesque than American elm and is susceptible to Dutch elm disease.
Habitat
Floodplain (river or stream floodplains), forests, talus and rocky slopes
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.
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Characteristics
- Habitat
- terrestrial
- 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 (i.e., 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
- 80–160 mm
- Leaf blade width
- 50–75 mm
- Leaf stalk
- the leaves have leaf stalks
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Bark texture
-
- the bark of an adult plant is ridged or plated
- the bark of an adult plant peels off easily or hangs off
- Twig winter color
-
- brown
- gray
- red
- Bud scale number
- there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed
-
Buds or leaf scars
- Bud scale number
- there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed
- 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 conical (cone-shaped)
- the winter buds are ovoid (egg-shaped)
- Winter bud stalks
- the winter buds have no stalks
-
Flowers
- Anther color
- 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 appearance
- the flowers appear before the leaves
- Flower petal color
-
- red
- yellow or green
- Flower symmetry
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- Hairs on ovary (Amelanchier)
- NA
- Inflorescence position
- the inflorescences grow on older branches
- Inflorescence type
- the inflorescence is a fascicle (compact cluster of 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 includes only one cycle of petals or sepals
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal fusion
- the perianth parts are fused to form a tube, cup, or bell shape
- Sepal appearance
- the sepals resemble petals in color and texture
- Sepal cilia (Ilex)
- NA
- Sepal tip glands
- there are no glands at the tips of the sepal lobes
- Sepals fused only to sepals
- the sepals are fused to each other (not other flower parts), at least near their bases
- Stamen number
-
- 5
- 6
- 7
- 8
- 9
- Stamen position relative to petals
- the stamens are lined up with the sepals (antesepalous)
- Stamens fused
- the stamens are not fused to one another
-
Fruits or seeds
- Berry color
- NA
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
- the fruit is an achene (dry, usually 1-seeded, does not separate or split open at maturity)
- Nut with spines (Fagaceae)
- NA
- Wings on fruit
- the fruit has one or more wings on it
-
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
- Hairs on upper side of leaf blade
- 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 cordate (heart-shaped, with rounded lobes)
- the base of the leaf blade is rounded
- the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)
- Leaf blade base symmetry
- the leaf blade base is asymmetrical
- Leaf blade bloom
- the underside of the leaf has no noticeable bloom
- 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
- 80–160 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 oblong (rectangular but with rounded ends)
- the leaf blade is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade texture
-
- the leaf blade is chartaceous (thin and dry like paper)
- 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
- 50–75 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
- there are no nectaries on the leaf stalk
- Leaf stalk shape
- the leaf stalk is not flattened
- Leaf teeth
- the leaf blade margin has teeth, which themselves have smaller teeth on them
- Leaf teeth hairs (Carya)
- NA
- Leaf type
- the leaf blade is simple (i.e., 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 (i.e., 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
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- forests
- river or stream floodplains
- talus or rocky slopes
-
Scent
- Plant odor
-
- the plant does not have much of an odor, or it has an unpleasant or repellant odor
- the plant has a pleasantly aromatic odor
-
Stem, shoot, branch
- Aerial roots
- the plant has no aerial roots
- Bark texture
-
- the bark of an adult plant is ridged or plated
- the bark of an adult plant peels off easily or hangs off
- Branch brittleness (willows only)
- NA
- 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
- 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
- red
- 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
Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)
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.
- Maine
- historical (S-rank: SH), potentially extirpated (code: PE)
- Massachusetts
- fairly widespread (S-rank: S4)
From Flora Novae Angliae dichotomous key
6. Ulmus rubra Muhl. N
slippery elm. Ulmus fulva Michx. • CT, MA, ME, NH, RI, VT; absent from much of ME. Rich, deciduous and riparian forests, rocky slopes. Ulmus rubra is sometimes confused with U. americana when collected later in the growing season (i.e., when vegetative). The outer bark is a useful character to separate these two species. The outer bark of U. rubra has contrasting light and dark layers when viewed in cross-section, that of U. americana does not.
Native to North America?
Yes
Sometimes confused with
- Ulmus americana:
- leaf blade with usually no (infrequently with 1) lateral veins forking well before reaching margin and wing of fruit with marginal cilia and lacking hairs over body of seed (vs. U. rubra, with leaf blade with usually 2 or more lateral veins forking well before reaching margin and wing of fruit lacking marginal cilia and hairy over the body of seed).
- Ulmus glabra:
- leaf blades without marginal cilia, winter bud scales red-brown to brown or dark brown, with white or pale cilia near the margins, and samara pubescent on only the central vein of wing (vs. U. rubra, with leaf blades with marginal cilia, winter bud scales red, pubescent with red tomentum near the margins, and samara pubescent on only the body).
Synonyms
- Ulmus fulva Michx.