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- Acalypha rhomboidea
Acalypha rhomboidea — common three-seeded-Mercury
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Facts
Common three-seeded Mercury can be distinguished from Virginia three-seeded Mercury (Acalypha virginica) by the number of lobes on the large carpellate bracts: this species has five to nine lobes while Virginia three-seeded Mercury has nine to fifteen.
Habitat
Anthropogenic (man-made or disturbed habitats), forests, 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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Flower petal color
- NA
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade edges
- the edge of the leaf blade has teeth
- Flower symmetry
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- Number of sepals, petals or tepals
-
- there are four petals, sepals, or tepals in the flower
- there are three petals, sepals, or tepals in the flower
- Stamen number
-
- 10
- 11
- 12
- 13 or more
- 8
- 9
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit length
- 2 mm
-
Clonal plantlets
- Bulbils
- the plant does not appear to have bulbils
- Bulblets replace flowers
- there are no bulblets where the flowers are located
-
Flowers
- Anther spurs
- the anthers do not have spurs on them
- Carpels fused
- the carpels are fused to one another
- Cilia on petals
- NA
- Cleistogamous flowers
- there are no cleistogamous flowers on the plan
- Corolla morphology
- NA
- Corolla palate
- NA
- Corona lobe length
- 0 mm
- Epicalyx
- the flower does not have an epicalyx
- Epicalyx number of parts
- 0
- Filament surface
- the filament is smooth, with no hairs or scales
- Flower description
- the flower has a superior ovary, and lacks a hypanthium
- Flower petal color
- NA
- Flower reproductive parts
- the flower has either only pollen- or only seed-producing parts
- Flower symmetry
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- Flowers sunken into stem
- no
- Form of style
- the style is branched above the base
- Fringed petal edges
- NA
- Fused stamen clusters
- NA
- Hairs on inflorescence
- at least some of the hairs on the axis of the inflorescence have glands
- Horns in hoods (Asclepias)
- NA
- Hypanthium
- the flower does not have a hypanthium
- Hypanthium length
- 0 mm
- Inflorescence one-sided
- the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
- Inner tepals (Rumex)
- NA
- Interior flower disk
- the flower does not have an interior disc
- Marks on petals
- NA
- Nectar spur
- the flower has no nectar spurs
- Number of branches in umbel
- 0
- Number of carpels
- 3
- Number of sepals, petals or tepals
-
- there are four petals, sepals, or tepals in the flower
- there are three petals, sepals, or tepals in the flower
- Number of styles
- 3
- 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 and sepal colors
- green to brown
- Petal appearance
- NA
- Petal base
- NA
- Petal folds or pleats
- NA
- Petal glandular dots or scales
- NA
- Petal hairs (Viola)
- NA
- Petal hairs on inner/upper surface
- NA
- Petal length
- 0 mm
- Petal length relative to sepals
- NA
- Petal nectaries
- NA
- Petal number
- 0
- Petal shape
- NA
- Petal tip shape
- NA
- Petal tips (Cuscuta)
- NA
- Petal width
- 0 mm
- Raceme attachment (Veronica)
- NA
- Reproductive system
- each flower has only carpels or only stamens, but both types of flower are present on each plant (monoecious)
- Scales inside corolla
- NA
- Sepal and petal color
- NA
- Sepal appearance
- the sepals are green or brown, and leaf-like in texture
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal number
- 3–5
- Sepal texture
- the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture
- Spur length
- 0 mm
- Spur number
- NA
- Stamen attachment
- the stamens are not attached to the petals or tepals
- Stamen number
-
- 10
- 11
- 12
- 13 or more
- 8
- 9
- Stamens fused
- the stamens are attached to one another at or near their bases
- Staminodes
- there are no staminodes on the flower
- Style petal-like
- the styles are not petal-like
- Umbel flower reproductive parts
- NA
- Upper lip of bilabiate corolla
- NA
-
Fruits or seeds
- Achene relative orientation
- NA
- Achene shape
- NA
- Achene surface (Polygonum)
- NA
- Achene type
- NA
- Berry color
- NA
- Capsule color (Viola)
- NA
- Capsule ribs
- NA
- Capsule splitting
-
- NA
- the capsule splits by three main valves, teeth or pores
- Carpel beak length
- 0 mm
- Fruit (pyxis) dehiscence
- NA
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 2 mm
- Fruit locules
- three
- Fruit shape
- the fruit is spherical
- 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)
- Fruit width
- 2 mm
- Hairs on fruit
- the fruits have hairs on them
- Legumes (Fabaceae)
- NA
- Mericarp length
- anything
- Mericarp segment shape (Desmodium)
- NA
- Other markings on berry
- NA
- Ovary stipe
- the ovary or fruit does not have a stipe
- Placenta arrangement
- the plant has axile placentation, in which the ovules are attached where the septa of a compound ovary are united, usually on the central axis, or to the septa themselves
- Rows of seeds in fruit (Brassicaceae)
- NA
- Schizocarpic fruit segments
- anything
- Seed length
- 1–2 mm
- Seed number
- 3
- Seed relative length
- the seed is longer than it is wide
- Seed surface
- the seed is smooth or without clear markings
- Septum in fruit (Brassicaceae)
- NA
- Wings on fruit
- the fruit does not have wings on it
- prickles on fruits
- the fruits do not have thorn-like defensive structures
-
Glands or sap
- Glands on leaf blade
- the leaf blades do not have glandular dots or scales
- Sap
- the sap is clear and watery
- Sap color
- the sap is clear
-
Growth form
- Growth form
- the plant is an herb (it has self-supporting stems)
- Lifespan
- the plant lives only a single year or less
- Parasitism
- the plant is not parasitic
- Plant color
- the leaves or young stems of the plant are green
- Plants darken when dry
- no
- Spines on plant
- the plant has no spines
- Underground organs
- there is a thickened taproot on the plant
-
Leaves
- Bracteole number (Apiaceae)
- 0
- Bracts in plantain (Plantago)
- NA
- Final leaf segment length (compound lvs only)
- 0 mm
- Final leaf segment length to width ratio (compound lvs only)
- 0
- Final leaf segment width (compound lvs only)
- 0 mm
- Floral bract texture
- the floral bracts are green, with a leaf-like texture
- Floral bracts
- the flower has one or more bracts associated with it
- Hairs on underside of leaf
- the underside of the leaf is fuzzy or hairy
- Hairs on upper side of leaf
- the upper side of the leaf is fuzzy or hairy
- Hooked hairs on underside of leaf
- no
- Inflated hairs on leaf
- the leaf blade does not have inflated hairs on it
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade base
- the leaf has a distinct leaf stalk (petiole)
- 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 teeth
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- the leaf blade has simple hairs with no glands, and not tangled or wooly
- Leaf blade length
- 30–90 mm
- Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
- Leaf blade shape
-
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade texture
- the leaf blade is herbaceous (has a leafy texture)
- Leaf blade vein pattern
- the major veins of the leaf blade branch, but do not rejoin
- Leaf blade width
- 15–50 mm
- Leaf duration
- the leaves drop off in winter (or they whither but persist on the plant)
- Leaf form
- the leaves are green, with an expanded blade and a leaf-like texture
- Leaf hair orientation
- the hairs are flat against the leaf surface, mostly pointing towards the leaf tip
- Leaf shiny
- the upper side of the leaf is dull or slightly shiny
- Leaf spines
- there are no spines on the leaf edges
- 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 base
- the petiole base is narrow where it attaches to the stem
- Leaf stalk length
- 7–70 mm
- Leaf teeth and lobes
-
- the leaf blade margin has outward-pointing teeth
- the leaf blade margin has rounded teeth
- Leaf tip
- the tip of the leaf blade is obtuse (bluntly pointed)
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf types
- NA
- Leaf variation
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaflet number
- 0
- Leaflet petiolules
- NA
- Leaves per node
- there is one leaf per node along the stem
- Pinnately compound leaf type
- NA
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Stipels
- NA
- Stipule features
- NA
- Stipule shape
-
- the stipules are another shape than the choices given
- the stipules are lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- Stipules
- the plant has stipules
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- forests
- man-made or disturbed habitats
- meadows or fields
- shores of rivers or lakes
-
Scent
- Plant odor
- the plant does not have much of a smell
-
Stem, shoot, branch
- Branched tendrils
- NA
- Direction of stem hairs
- NA
- Hair between stem nodes
- the stem has no hairs between the nodes
- Hairs between stem nodes
- the stem has no hairs between the nodes
- Hooked hairs on stem between nodes
- no
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Length of hairs between stem nodes
- 0 mm
- Plant height
- 20–60 cm
- Stem bloom
- there is no powdery or waxy film on the stem
- Stem hair distribution
- NA
- Stem orientation
- the stems are upright or angled outwards
- Stem roughness between nodes
- the stem does not feel rough
- Tendril origin
- NA
- Tendrils
- the plant does not have tendrils
- Wings on stem
- the stem does not have wings on it
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
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
- fairly widespread (uncertain) (S-rank: S4?)
From Flora Novae Angliae dichotomous key
2. Acalypha rhomboidea Raf. N
common three-seeded-Mercury. Acalypha virginica L. var. rhomboidea (Raf.) Cooperrider • CT, MA, ME, NH, RI, VT. Fields, roadsides, riparian forests, river banks, gardens, waste areas. Levin (1999) noted that about 5% of plants he examined from North America showed hirsute pubescence on the stems, a character state normally associated with Acalypha virginica.
Native to North America?
Yes
Sometimes confused with
- Acalypha gracilens:
- leaf blades linear to narrow-oblong, on leaf stalks 2-14 mm long that are up to 1/4 as long as the leaf blade (vs. A. rhomboidea, with leaf blades broad-lanceolate to ovate, on leaf stalks 7-70 mm long that are more than 1/3 as long as the leaf blade).
- Acalypha virginica:
- carpellate bracts with 9-15 lobes, pubescent with long eglandular hairs and sometimes short glandular ones, and petioles 23-66% as long as the leaf blades (vs. A. rhomboidea, with carpellate bracts with 5-9 lobes, pubescent with long stipitate glands, and petioles 34-89% as long as the leaf blades, commonly more than 50%).
Synonyms
- Acalypha virginica var. rhomboidea (Raf.) Cooperrider