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Cuscuta polygonorum — smartweed dodder

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Facts

Smartweed dodder is a native species that is very rare in New England. Although named for one of its hosts, smartweed or knotweed (Polygonum), it parasitizes a wide range of herbaceous plants. In New England it is known from Connecticut and Massachusetts.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Massachusetts
Flower petal color
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
  • NA
  • 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
Fruit type (general)
  • the fruit is dry and splits open when ripe
  • the fruit is dry but does not split open when ripe
Fruit length
2–2.5 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 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 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
    Cleistogamous flowers
    there are no cleistogamous flowers on the plan
    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
    white
    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 flower has two or more completely separate styles
    Fused stamen clusters
    NA
    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
    Inflorescence one-sided
    the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
    Inner tepals (Rumex)
    NA
    Nectar spur
    the flower has no nectar spurs
    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
    Ovary position
    the ovary is above the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal and sepal colors
    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 hairs (Viola)
    NA
    Petal number
    4–5
    Petal tips (Cuscuta)
    the tips of the petals stand up straight or slant outwards
    Reproductive system
    all the flowers have both carpels and stamens (synoecious)
    Scales inside corolla
    no
    Sepal and petal color
    the sepals are different from the petals
    Sepal appendages
    the sepals do not have appendages on them
    Sepal appendages (Oenothera)
    NA
    Sepal number
    4–5
    Stamen attachment
    the stamens are attached at or near the bases of the petals or tepals
    Stamen number
    • 4
    • 5
    Stamen position relative to petals
    the stamens are lined up with the sepals
    Staminodes
    there are no staminodes on the flower
    Umbel flower reproductive parts
    NA
    Upper lip of bilabiate corolla
    NA

  • Fruits or seeds

    Achene relative orientation
    NA
    Achene shape
    NA
    Achene surface (Polygonum)
    NA
    Achene type
    NA
    Berry color
    NA
    Capsule color (Viola)
    NA
    Capsule ribs
    the capsule has no prominent ribs or wings
    Capsule splitting
    NA
    Fruit (pyxis) dehiscence
    • NA
    • the pyxis bursts open or shatters without a clear seam
    Fruit features (Brassicaceae)
    NA
    Fruit length
    2–2.5 mm
    Fruit locules
    two
    Fruit type (general)
    • the fruit is dry and splits open when ripe
    • the fruit is dry but does not split open when ripe
    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 axile placentation, in which the ovules are attached where the septa of a compound ovary are united, usually on the central axis, or to the septa themselves
    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
    • NA
    • 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

    Horizontal rooting stem
    the plant does not have stolons
    Lifespan
    the plant lives only a single year or less
    Parasitism
    the plant is parasitic on other plants (partially or completely dependent on other plants to supply nutrients)
    Plant color
    the plant lacks green pigments, even on the leaves or young stems
    Plants darken when dry
    no
    Spines on plant
    the plant has no spines

  • Leaves

    Bracteole number (Apiaceae)
    0
    Bracts in plantain (Plantago)
    NA
    Final leaf segment length to width ratio (compound lvs only)
    0
    Final leaf segment width (compound lvs only)
    0 mm
    Hairs on underside of leaf
    the underside of the leaf is not hairy, or it has very few hairs
    Leaf arrangement
    alternate: there is one leaf per node along the stem
    Leaf blade base
    the leaf has no stalk
    Leaf blade edges
    • NA
    • the edge of the leaf blade is entire (has no teeth or lobes)
    Leaf blade surface colors
    • NA
    • the upper side of the leaf blade is relatively uniform in color
    Leaf duration
    the leaves drop off in winter (or they whither but persist on the plant)
    Leaf form
    the leaves are small and thin and lack leaf stalks
    Leaf spines
    • NA
    • there are no spines on the leaf edges
    Leaf stalk attachment to leaf
    NA
    Leaf stalk base
    NA
    Leaf teeth and lobes
    • NA
    • 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 types
    NA
    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 (i.e., lobed or unlobed but not separated into leaflets)
    Stipule features
    NA
    Stipules
    there are no stipules on the plant

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields

  • 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
    Hairs between stem nodes
    the stem has no hairs between the nodes
    Hooked hairs on stem between nodes
    no
    Leaves on stem
    NA
    Stem roughness between nodes
    the stem does not feel rough
    Tendril origin
    NA
    Tendrils
    the plant does not have tendrils

Wetland status

Not classified

In New England

Distribution

Connecticut
present
Maine
absent
Massachusetts
present
New Hampshire
absent
Rhode Island
absent
Vermont
absent

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
extremely rare (uncertain) (S-rank: S1?)
Rhode Island
extremely rare (S-rank: S1), concern (uncertain) (code: C*)

From Flora Novae Angliae dichotomous key

11.  Cuscuta polygonorum Engelm. NC

smartweed dodder. Cuscuta chlorocarpa Engelm. • CT, MA; also reported from ME by Campbell et al. (1995) and RI by Seymour (1982), but specimens are unknown. Parasitic on various tracheophytes, especially coarse herbaceous types.

Native to North America?

Yes

Sometimes confused with

Cuscuta coryli:
calyx lobes acute at the apex and corolla lobes granulate-textured, the tips of the lobes inflexed (vs. C. polygonorum, with calyx lobes obtuse at the apex and corolla lobes relatively smooth, with erect or ascending tips of the lobes).
Cuscuta cephalanthi:
corolla lobes obtuse to rounded at the apex and the tips of the corolla lobes not reaching the sinuses between the corolla lobes (vs. C. polygonorum, with corolla lobes acute to acuminate at the apex and the tips of the calyx lobes reaching or surpassing the sinuses between the corolla lobes).

Synonyms

  • Cuscuta chlorocarpa Engelm.

Family

Convolvulaceae

Genus

Cuscuta