Persicaria maculosa S.F. Gray

lady's-thumb smartweed

New England Distribution

Adapted from BONAP data

Where native and non-native distributions co-occur in a county, only the native distribution is shown.

North America Distribution

Adapted from BONAP data

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Facts About

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

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 petals
the petals are fused into a corolla tube
Stamen number
  • 4
  • 5
  • 6
  • 7
  • 8
Fruit type (general)
the fruit is dry but does not split open when ripe
Fruit length
1.9–2.7 mm
Show All Characteristics
  • 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 petals
    the petals are fused into a corolla 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 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)
    Sepal and petal color
    the petals and sepals are similar
    Sepal appearance
    the sepals resemble petals in color and texture
    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
    NA
    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

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

New England Distribution and Conservation Status

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)

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.

Family

Polygonaceae

Genus

Persicaria

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Information from Dichotomous Key of Flora Novae Angliae

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.