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- Rubiaceae
- Cephalanthus
- Cephalanthus occidentalis
Cephalanthus occidentalis — common buttonbush
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Facts
Common buttonbush produces spherical buttons of white flowers amidst its opposite, shiny green leaves. The Latin name of the genus means "head" (Cephal-) and "flower" (-anthos). This distant relative of coffee (family Rubiaceae) grows in wetland areas. Ducks and other waterfowl eat the seeds.
Habitat
Anthropogenic (man-made or disturbed habitats), riverine (in rivers or streams), shores of rivers or lakes, swamps, 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
-
- aquatic
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Growth form
- the plant is a shrub (i.e., a woody plant with several stems growing from the base)
- Leaf type
- the leaf blade is simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaves per node
-
- there are three leaves per node along the stem
- there are two leaves 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
- 80–150 mm
- Leaf blade width
- 23–150 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 is thin and smooth
- Twig winter color
-
- brown
- gray
- red
- Bud scale number
- there are no scales on the winter buds
-
Buds or leaf scars
- Bud position relative to scar
- the winter bud has a leaf scar just below it
- Bud scale number
- there are no scales on the winter buds
- Bud scar shape (Fraxinus)
- NA
- Collateral buds
- there are no collateral buds on the sides of the branches
- Leaf scar arrangement
-
- there are three or more leaf scars per node on the stem or twig
- there are two leaf scars per node on the stem or twig
- Superposed buds
- there are no superposed buds on the branch
- 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 petal color
- white
- Flower symmetry
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- Hairs on ovary (Amelanchier)
- NA
- Hypanthium present
- the flower has a hypanthium
- Inflorescence hairs
- there are no hairs on the inflorescence
- Inflorescence position
- the inflorescences grow on the twigs
- Inflorescence type
- the inflorescence differs from the choices given
- Number of pistils
- 1
- Ovary position
- the ovary is below 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 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
- 4
- 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 a schizocarp (when dry it splits into sections, each holding one or more seeds)
- 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
- 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 (i.e., a woody plant with several stems growing from the base)
-
Leaves
- Hairs on underside of leaf blade
- the underside of the leaf has no hairs
- 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 cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
- the base of the leaf blade is rounded
- Leaf blade base symmetry
- the leaf blade base is symmetrical
- Leaf blade bloom
- the underside of the leaf has no noticeable bloom
- Leaf blade edges
- the edge of the leaf blade has no teeth or lobes
- Leaf blade edges (Acer)
- NA
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- NA
- Leaf blade length
- 80–150 mm
- Leaf blade scales
- there are no scales on the leaf blades
- Leaf blade shape
-
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is oblong (rectangular but with rounded ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade 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
- 23–150 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 edge of the leaf blade is entire (has no teeth or lobes)
- 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 are three leaves per node along the stem
- there are two leaves per node along the stem
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
- Stipules
- the plant has stipules
-
Place
- Habitat
-
- aquatic
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- edges of wetlands
- in rivers or streams
- man-made or disturbed habitats
- shores of rivers or lakes
- swamps
-
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
- the bark of an adult plant is thin and smooth
- 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
- 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 few or no hairs on them
- 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 only in wetlands. (Wetland indicator code: OBL)
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
- widespread (S-rank: S5)
From Flora Novae Angliae dichotomous key
1. Cephalanthus occidentalis L. N
common buttonbush. Cephalanthus occidentalis L. var. pubescens Raf. • CT, MA, ME, NH, RI, VT. Pond shores, slow-moving rivers, swamps, ditches.
Native to North America?
Yes
Synonyms
- Cephalanthus occidentalis var. pubescens Raf.