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- Persicaria
- Persicaria lapathifolia
Persicaria lapathifolia — dock-leaved smartweed
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Facts
Dock-leaved smartweed is a widespread annual that is native to North America and Eurasia. It has been used in traditional medicine by the Apache, Keres, Navajo, Potawatomi, and Zuni.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields, 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
- 
                                
                                    - 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
- 
                                
                                    - 5
- 6
 
- 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
- 1.5–3.2 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 color
- 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
- 3–4 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
- 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
- the flower has a hypanthium
 
 - Inflorescence length
- 30–80 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
- 5–12 mm
 - Inner tepals (Rumex)
- NA
 - Length of flower stalk
- 0.5–2.3 mm
 - Length of peduncle
- 2–25 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
- yes
 
 - Petal hairs (Viola)
- NA
 - Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
 - Petal length
- 2.5–3 mm
 - Petal number
- 2
 - Petal shape
- 
                                
                                    - the petal outline is elliptic (shaped like an ellipse; widest near the middle and tapering at both ends)
- 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 length
- 2.5–3 mm
 - Sepal number
- 2–3
 - Sepal shape
- 
                                
                                    - the sepal outline is eliiptic (widest near the middle and tapering at both ends)
- 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
- 
                                
                                    - 5
- 6
 
 - 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 circular 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
- 1.5–3.2 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
- 1.1–1.25
 - Fruit locules
- one
 - Fruit shape
- the fruit is flat or strongly compressed
 - 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
- 1.6–3 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 number (Apiaceae)
- 0
 - Bracteole shape
- the bracteoles are ovate (widest below the middle, and broadly tapering to both ends--egg-shaped)
 - 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
 - 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)
 - 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 tangled or woolly-looking hairs
 - Leaf blade length
- 40–220 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)
 - Leaf blade surface colors
- 
                                
                                    - the upper side of the leaf blade has obvious spots, mottles or stripes
- 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 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
- 3–60 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
- 1–16 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)
 - 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 do not have tiny hairs (cilia) at their tips
 
 - Stipule length
- 4–35 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
- 
                                
                                    - edges of wetlands
- man-made or disturbed habitats
- meadows or fields
- shores of rivers or lakes
- swamps
 
 
- 
                        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
- the hairs point mostly upwards to outwards
 
 - 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
- 
                                
                                    - at least some of the hairs on the stem have glands
- 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
- 5–100 cm
 - Stem bloom
- there is no powdery or waxy film on the stem
 - Stem nodes swollen
- the stem is swollen at the nodes
 - 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 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.
- Massachusetts
- unranked (S-rank: SNR)
var. lapathifolium
- Massachusetts
- unranked (S-rank: SNR)
var. salicifolium
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
8. Persicaria lapathifolia (L.) S.F. Gray N
dock-leaved smartweed. Persicaria tomentosa (Schrank) Bickn.; Polygonum lapathifolium L.; P. lapathifolium L. var. ovatum A. Braun; P. lapathifolium L. var. prostratum C.F.H. Wimmer; P. lapathifolium L. var. salicifolium Sibthorp; P. scabrum Moench • CT, MA, ME, NH, RI, VT. Fields, roadsides, waste areas, shorelines, ditches, swamps, river banks. This species is a widespread diploid native to the New and Old World.
Native to North America?
Yes
Synonyms
- Persicaria tomentosa (Schrank) Bickn.
- Polygonum lapathifolium L.
- Polygonum lapathifolium L. var. ovatum A. Braun
- Polygonum lapathifolium L. var. prostratum C.F.H. Wimmer
- Polygonum lapathifolium L. var. salicifolium Sibthorp
- Polygonum scabrum Moench
 
                         
                         
                        ![Fruits: Persicaria lapathifolia. ~ By Arthur Haines. ~ Copyright © 2025 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Polygonaceae/persicaria-lapathifolia-fr-ahaines-b.jpg) 
                        ![Plant form: Persicaria lapathifolia. ~ By Arthur Haines. ~ Copyright © 2025 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Polygonaceae/persicaria-lapathifolia-ha-ahaines-a.jpg) 
                         
                         
                         
                        ![Additional features: Persicaria lapathifolia. ~ By Elizabeth Farnsworth. ~ Copyright © 2025 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-239x239/Polygonaceae/persicaria-lapathifolia-af-efarnsworth.jpg) 
                         
                         
                         
                         
                         
                         
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