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- Persicaria setacea
Persicaria setacea — bristly smartweed
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Facts
Bristly smartweed is a rare plant of pond shores, streams and marshes along the coastal plain in Massachusetts and Rhode Island. A population was also recorded from Hampden County, Massachusetts, inland and disjunct from the others, but is no longer thought to exist. This semi-aquatic, perennial plant needs periodic flooding to eliminate competing plants, and its uncommon habitats are vulnerable to drought and trampling. Its greenish-white flowers (produced in July to mid-September) and hairy-bristly ochrea (a cylindrical sptipule wrapping the stem at the leaf nodes) distinguish it from the more common P. hydropiperoides, with which it sometimes co-occurs.
Habitat
Marshes, 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
-
- aquatic
- wetlands
- New England state
-
- Massachusetts
- Rhode Island
- Flower petal color
-
- green to brown
- white
- 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 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
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Stamen number
- 5
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit length
- 1.5–2.5 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 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
- 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 petal color
-
- green to brown
- white
- Flower reproductive parts
-
- the flower has both pollen- and seed-producing 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
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Horns in hoods (Asclepias)
- NA
- Hypanthium
-
- the flower does not have a hypanthium
- the flower has a hypanthium
- Inflorescence length
- 20–80 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
- 4–8 mm
- Inner tepals (Rumex)
- NA
- Nectar spur
- the flower has no nectar spurs
- 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
- Number of styles
- 1–3
- 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)
- the perianth is cupuliform (cup-shaped)
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal and sepal colors
-
- green to brown
- white
- Petal appearance
-
- the petals are green and/or leafy in texture
- 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 hairs (Viola)
- NA
- Petal tips (Cuscuta)
- 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 are green or brown, and leaf-like in texture
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal color
- green to brown
- Sepal number
- 5
- 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
- Stamen position relative to petals
- NA
- 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
- 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
- Fruit (pyxis) dehiscence
- NA
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 1.5–2.5 mm
- Fruit locules
- one
- 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)
- 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
- 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
- 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)
- Horizontal rooting stem
-
- the plant does not have stolons
- the plant has stolons
- Lifespan
- the plant lives more than two years
- 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
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
-
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
- 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
- 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
- the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade length
- 30–180 mm
- 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 is relatively uniform in color
- Leaf blade width
- 1.5–4.8 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 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 teeth and lobes
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf variation
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaflet number
- 0
- 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
-
- 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 fused to leaf stalk
- the stipules are fused to the petioles for some or most of their length
- Stipule shape
- the stipules are tubular (cylindrical and hollow)
- Stipules
- the plant has stipules
-
Place
- Habitat
-
- aquatic
- wetlands
- New England state
-
- Massachusetts
- Rhode Island
- Specific habitat
-
- marshes
- shores of rivers or lakes
-
Scent
- Plant odor
- the plant does not have much of a smell
-
Stem, shoot, branch
- Branched tendrils
- NA
- 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
- 50–150 cm
- Stem hair distribution
- the hairs on the stem are mainly found at the nodes
- Tendril origin
- NA
- Tendrils
- the plant does not have tendrils
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- present
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- rare (S-rank: S2), threatened (code: T)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
From Flora Novae Angliae dichotomous key
20. Persicaria setacea (Baldw.) Small NC
bristly smartweed. Persicaria setacea (Baldw.) Small var. interjecta (Fern.) C.F. Reed; P. setacea (Baldw.) Small var. tonsa (Fern.) C.F. Reed; Polygonum hydropiperoides Michx. var. setaceum (Baldw.) Gleason; P. setaceum Michx. var. interjectum Fern.; P. setaceum Michx. var. tonsum Fern. • MA, RI; primarily on the coastal plain, disjunct in Hamden County, MA. Pond shores, streams, marshes. Our specimens in New England are much closer to Persicaria hydropiperoides than many treatments present (as evidenced by the characters they use in their identification keys).
Native to North America?
Yes
Sometimes confused with
- Persicaria hydropiperoides:
- hairs of sheathing stipules gradually enlarged at base, adnate to stipule for 28-66% of their total length, and perianth usually pink to red or cream-white, rarely purple or green-white to green (vs. P. setacea, with the hairs of the sheathing stipules conspicuously enlarged at base, adnate to the stipule for mostly 13–28% of their total length, and perianth green-white to green).
Synonyms
- Persicaria setacea (Baldw.) Small var. interjecta (Fern.) C.F. Reed
- Persicaria setacea (Baldw.) Small var. tonsa (Fern.) C.F. Reed
- Polygonum hydropiperoides Michx. var. setaceum (Baldw.) Gleason
- Polygonum setaceum Michx. var. interjectum Fern.
- Polygonum setaceum Michx. var. tonsum Fern.