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- Persicaria
- Persicaria maculosa
Persicaria maculosa — lady's-thumb smartweed
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Facts
Lady's-thumb smartweed is an annual weed of wet disturbed areas. The Cherokee used the crushed leaves to treat rash caused by poison ivy.
Habitat
Anthropogenic (man-made or disturbed habitats), 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
- Rhode Island
- Vermont
- Flower petal color
-
- green to brown
- pink to red
- white
- Leaf type
- the leaves are simple (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 is entire (has no teeth or lobes)
- 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 five petals, sepals, or tepals in the flower
- there are four petals, sepals, or tepals in the flower
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Stamen number
-
- 4
- 5
- 6
- 7
- 8
- Stem nodes swollen
- the stem is swollen at the nodes
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit length
- 1.9–2.7 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 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
- Anther opening
- the anthers have narrow slits or furrows that run lengthwise along the anthers
- Anther spurs
- the anthers do not have spurs on them
- Calyx growth after flowering
- the calyx does not grow to cover or partially cover the fruit
- Calyx symmetry
- there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
- Carpels fused
- the carpels are fused to one another
- Cilia on petals
- the petal margins do not have cilia
- Corolla palate
- no
- 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 length
- 2–3.5 mm
- Flower orientation
- the flower points upwards or is angled outwards
- Flower petal color
-
- green to brown
- pink to red
- white
- Flower reproductive parts
- the flower has both pollen- and 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
- the petals are not fringed
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Hairs on inflorescence
- the axis of the inflorescence has no hairs on it
- Horns in hoods (Asclepias)
- NA
- Hypanthium
-
- the flower does not have a hypanthium
- the flower has a hypanthium
- Inflorescence length
- 10–60 mm
- Inflorescence one-sided
- the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
- Inflorescence width
- 7–12 mm
- Inner tepals (Rumex)
- NA
- Length of flower stalk
- 1–2.5 mm
- Length of peduncle
- 10–50 mm
- Marks on petals
- there are no noticeable marks on the petals
- Nectar spur
- the flower has no nectar spurs
- Number of branches in umbel
- 0
- Number of carpels
- 2–3
- Number of pistils
- 1
- Number of sepals, petals or tepals
-
- there are five petals, sepals, or tepals in the flower
- there are four petals, sepals, or tepals in the flower
- Number of styles
- 2–3
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Perianth shape
- the perianth is campanulate (bell-shaped, with a tube about as long as wide, flaring at the mouth)
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal and sepal colors
-
- green to brown
- pink to red
- white
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal folds or pleats
- the petals of the flower do not have folds or plaits
- Petal glandular dots or scales
- no
- Petal hairs (Viola)
- NA
- Petal length
- 2–3.5 mm
- Petal number
- 2
- Petal shape
- the petal outline is obovate (roughly egg-shaped, but with the widest point above the middle of the leaf blade)
- Petal tip shape
-
- the petal tip is obtuse (bluntly pointed)
- the petal tip is rounded
- Petal tips (Cuscuta)
- NA
- Raceme attachment (Veronica)
- NA
- Reproductive system
- all the flowers have both carpels and stamens (synoecious)
- Scales inside corolla
- no
- Sepal and petal color
- the petals and sepals are similar
- Sepal appearance
- the sepals resemble petals in color and texture
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal cilia
- the sepals do not have cilia
- Sepal color
-
- green to brown
- pink to red
- white
- Sepal features
- NA
- Sepal length
- 2–3.5 mm
- Sepal number
- 2–3
- Sepal shape
- the sepal outline is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
- Sepal texture
- the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture
- Sepal tip shape
-
- the sepal tip is obtuse (is bluntly pointed)
- the sepal tip is rounded
- Sepal uniformity
- all the sepals are about the same size
- Sepals fused only to sepals
- the sepals are fused to each other (not other flower parts), at least near their bases
- Stamen morphology
- the stamens within each cycle are the same
- Stamen number
-
- 4
- 5
- 6
- 7
- 8
- Stamen relative length
- anything
- Staminodes
- there are no staminodes on the flower
- Style length
- Up to 2 mm
- 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
- the achenes are perpendicular to the plane of the perianth (vertical)
- Achene shape
-
- the achenes are another shape in outline
- the achenes are oval in outline
- Achene surface (Polygonum)
- NA
- Achene type
- the fruit is an achene (dry, indehiscent, and usually one-seeded)
- Berry color
- NA
- Capsule color (Viola)
- NA
- Capsule ribs
- NA
- Capsule splitting
- NA
- Carpel beak length
- 0 mm
- Fruit (pyxis) dehiscence
- NA
- Fruit cross-section
- the fruit is at least somewhat flattened
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 1.9–2.7 mm
- Fruit length relative to sepals
-
- the fruit is about the same length as its associated sepals
- the fruit is longer than its associated sepals
- the fruit is shorter than its associated sepals
- Fruit length to width ratio
- 1.2
- Fruit locules
- one
- Fruit stalk orientation
- the fruits point upward or spread or curve outward
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
- the fruit is an achene (dry, usually one-seeded, does not separate or split open at maturity)
- Fruit width
- 1.5–2.2 mm
- Hair type on fruit
- NA
- Hairs on fruit
- the fruits are not hairy
- Legumes (Fabaceae)
- NA
- Mericarp length
- 0 mm
- Mericarp segment shape (Desmodium)
- NA
- Other markings on berry
- NA
- Ovary stipe
- the ovary or fruit does not have a stipe
- Ovary stipe length
- 0 mm
- Placenta arrangement
- the plant has basal placentation, where one or a few ovules develop at the base of a simple or compound ovary
- Rows of seeds in fruit (Brassicaceae)
- NA
- Schizocarpic fruit compression
- NA
- Schizocarpic fruit segments
- 0
- Seed number
- 1
- 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
- the leaf blades 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)
- Horizontal rooting stem
- the plant does not have stolons
- 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 are only slender roots on the plant
-
Leaves
- Bracteole length
- 0.1–2.7 mm
- Bracteole number (Apiaceae)
- 0
- Bracteoles
- the plant has bracteoles between the primary bracts and the flowers
- 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
- NA
- Floral bracts
- the flower does not have bracts
- Flower bract length
- 0 mm
- Hairs on leaf stalk
-
- the petiole has hairs on it
- the petiole has no hairs on it
- Hairs on underside of leaf
-
- the underside of the leaf is fuzzy or hairy
- the underside of the leaf is not hairy, or it has very few hairs
- Hairs on upper side of leaf
-
- the upper side of the leaf is fuzzy or hairy
- the upper side of the leaf is not hairy, or it has very few hairs
- 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)
- the leaf has no stalk
- 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
- the underside of the leaf has no noticeable bloom
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- 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
- 10–180 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 has obvious spots, mottles or stripes
- 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 veins
- the leaf blade has one main vein running from the base towards the tip (it may or may not have secondary veins)
- Leaf blade width
- 2–40 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
- the leaves have no leaf stalks, but attach directly to the stem
- Leaf stalk attachment to leaf
-
- NA
- 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
- 1–8 mm
- Leaf teeth and lobes
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf tip
-
- the tip of the leaf blade is acuminate (tapers to a long, thin point)
- the tip of the leaf blade is acute (sharply pointed)
- Leaf type
- the leaves are simple (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 (lobed or unlobed but not separated into leaflets)
- Stipels
- NA
- Stipule features
-
- glabrous on the surface
- the stipules are hairy with hairs standing out at a 45 to 90 degree angle, or pressed to the stipule surface
- the stipules are straight (or somewhat slanted) across the top
- the stipules have a fringe of cilia along the top edge
- Stipule length
- 4–15 mm
- Stipule shape
- the stipules are tubular (cylindrical and hollow)
- Stipules
- the plant has stipules
- Teeth per side of leaf blade
- 0
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- 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
- the hairs are pressed flat against the plant, pointing towards the plant's tip
- Flowering stem cross-section
- the flowering stem is circular, or with lots of small angles so that it is roughly circular
- Hair between stem nodes
-
- the stem has hairs between the nodes
- the stem has no hairs between the nodes
- Hairs between stem nodes
-
- the hairs on the stem are plain, without glands or branches, and not tangled
- 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
- Plant height
- 5–130 cm
- Stem bloom
- there is no powdery or waxy film on the stem
- Stem hair distribution
- the hairs on the stem are distributed more of less uniformly
- Stem nodes swollen
- the stem is swollen at the nodes
- Stem orientation
-
- the stems are upright or angled outwards
- the stems trail at the base, but may turn upwards at the tips
- 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
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.
- Massachusetts
- not applicable (S-rank: SNA)
From Flora Novae Angliae dichotomous key
10. Persicaria maculosa S.F. Gray E
lady’s-thumb smartweed. Persicaria persicaria (L.) Small; P. vulgaris Webb & Moq.; Polygonum dubium Stein; P. persicaria L. • CT, MA, ME, NH, RI, VT. Fields, roadsides, waste areas, gardens, shorelines, ditches, yards.
Native to North America?
No
Sometimes confused with
- Persicaria longiseta:
- summit of sheathing stipule fringed with hairs mostly 1-4 mm long and leaf blades without dark blotches or marks on the upper surface (vs. P. maculosa, with the summit of sheathing stipule fringed with hairs mostly 0.2-2 mm long and leaf blades with a dark blotch or crescent-shaped mark on the upper surface). Persicaria pensylvanica: summit of tubular stipule without a fringe of long bristles and stalk of inflorescence usually with stipitate glands (vs. P. maculosa, with the summit of tubular stipule with a fringe of long bristle and stalk of inflorescence usually without stipitate glands).
Synonyms
- Persicaria persicaria (L.) Small
- Persicaria vulgaris Webb & Moq.
- Polygonum dubium Stein
- Polygonum persicaria L.