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• Persicaria setacea

Persicaria setacea — bristly smartweed

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

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 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)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae