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- Rhododendron canadense
Rhododendron canadense — Canada rosebay, rhodora
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Facts
Rhodora is a small shrub that brightens up bogs and wet woods with its gorgeous pink flowers, which emerge slightly earlier than the gray-green leaves. It is a host plant for the Columbia silkmoth (Hyalophora columbia) in Maine and the northwest. The flowers also attract bees.
Habitat
Anthropogenic (man-made or disturbed habitats), bogs, fens (calcium-rich wetlands), meadows and fields, shores of rivers or lakes
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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Growth form
- the plant is a shrub (a woody plant with several stems growing from the base)
- 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 no teeth or lobes
- 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
- 10–83 mm
- Leaf blade width
- 4–30 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 thin and smooth
- the bark of an adult plant peels off easily or hangs off
- Twig winter color
-
- brown
- 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
- Terminal bud
- the branch has a terminal bud on it
- 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 stalks
- the winter buds have no stalks
-
Flowers
- 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 at the same time as the leaves
- the flowers appear before the leaves
- Flower petal color
-
- pink
- red
- white
- 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 a corymb (with long lower branches and shorter upper branches, giving it a more or less flat-topped look)
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- the inflorescence is an umbel (with an axis so short it appears the flowers all originate from the same point)
- 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 two cycles of petal- or sepal-like structures
- 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 leaves in color and texture
- Sepal cilia (Ilex)
- NA
- Sepal tip glands
-
- there are glands at the tips of the sepal lobes
- 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
- 10
- Stamen position relative to petals
- NA
- Stamens fused
- the stamens are not fused to one another
-
Fruits or seeds
- Berry color
- NA
- Fruit tissue origin
- there are no flower parts that form part of the fruit
- 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 shrub (a woody plant with several stems growing from the base)
-
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 fuzzy or hairy
- Leaf blade base shape
-
- the base of the leaf blade is attenuate (tapering very gradually to a prolonged tip)
- 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 no teeth or lobes
- Leaf blade edges (Acer)
- NA
- Leaf blade flatness
- the edges of the leaf are curled under
- Leaf blade hairs
- the hairs on the leaf blade are different from the choices given
- Leaf blade length
- 10–83 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)
- Leaf blade texture
-
- the leaf blade is herbaceous (has a leafy texture)
- the leaf blade is membranaceous (thin, flexible, almost translucent)
- 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
- 4–30 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 has glands on the upper surface
- 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 edge of the leaf blade is entire (has no teeth or lobes)
- 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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- bogs
- fens (calcium-rich wetlands)
- man-made or disturbed habitats
- meadows or fields
- 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 thin and smooth
- 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 clearly lenticels on the 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
- Short shoots
- there are no peg- or knob-like shoots present
- Twig bloom
-
- the twig has bloom on it
- there is no bloom on the twig
- Twig hairs
-
- the twigs have few or no hairs on them
- the twigs have hairs with glands at their tips
- 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
- 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
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.
- Connecticut
- uncommon (S-rank: S3)
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
2. Rhododendron canadense (L.) Torr. N
rhodora. Azalea canadensis (L.) Kuntze; Rhodora canadensis L. • CT, MA, ME, NH, RI, VT. Bogs, acidic fens, peaty shorelines, swamps, low roadsides, pastures.
Native to North America?
Yes
Synonyms
- Azalea canadensis (L.) Kuntze
- Rhodora canadensis L.