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- Polygonaceae
- Rumex
- Rumex occidentalis
Rumex occidentalis — western dock
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Facts
Rumex occidentalis is native to North America and to portions of New England, though some populations are introduced in the Northeast.
Habitat
Marshes, shores of rivers or lakes, swamps
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
- wetlands
- New England state
-
- Maine
- Massachusetts
- Vermont
- Flower petal color
-
- green to brown
- pink to red
- 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 six 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
- 6
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit length
- 3–4.8 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 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
- pink to red
- 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 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
- the flower has 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)
- the inner tepals do not have tubercles on them
- Nectar spur
- the flower has no nectar spurs
- Number of pistils
- 1
- Number of sepals, petals or tepals
- there are six petals, sepals, or tepals in the flower
- Number of styles
- 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
- Petal appearance
- the petals are green and/or leafy in texture
- Petal folds or pleats
- the petals of the flower do not have folds or plaits
- Petal hairs (Viola)
- NA
- Petal number
- 3
- 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
- pink to red
- Sepal number
- 5–6
- Sepals fused only to sepals
- the sepals are fused to each other (not other flower parts), at least near their bases
- Stamen attachment
- the stamens are not attached to the petals or tepals
- Stamen number
- 6
- Stamen position relative to petals
- NA
- Stamens fused
- the stamens are not attached to one another
- 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 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
- 3–4.8 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
- the ovary or fruit has 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
- 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
-
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 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 a distinct leaf stalk (petiole)
- Leaf blade base shape
-
- the base of the leaf blade is cordate (heart-shaped, has rounded lobes at the base)
- the base of the leaf blade is rounded
- 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
- 100–350 mm
- Leaf blade shape
-
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is oblong (rectangular but with rounded ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- the leaf blade is triangular, with the stalk or attachment point on one of the sides
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade width
- 50–120 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)
- the leaf blade margin is wavy, but does not have teeth
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf variation
- the lower leaves are larger, toothier, and/or on longer stalks than the upper leaves
- 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
-
- glabrous on the surface
- the stipules do not have tiny hairs (cilia) at their tips
- Stipules
- the plant has stipules
-
Place
- Habitat
- wetlands
- New England state
-
- Maine
- Massachusetts
- Vermont
- Specific habitat
-
- marshes
- shores of rivers or lakes
- swamps
-
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 no hairs between the nodes
- Hairs between stem nodes
- 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
- 50–140 cm
- 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
- present
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- absent
- 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)
- Vermont
- historical (S-rank: SH)
From Flora Novae Angliae dichotomous key
11. Rumex occidentalis S. Wats. N│EC
western dock. Rumex aquaticus L. ssp. fenestratus (Greene) Hultén; R. aquaticus L. var. fenestratus (Greene) Dorn; R. aquaticus L. ssp. occidentalis (S. Wats.) Hultén; R. fenestratus Greene; R. occidentalis S. Wats. var. fenestratus (Greene) Lepage • MA, ME, VT. Swamps, marshes, shorelines. This species appears to be native in ME (Aroostook and Washington Counties) and VT, and introduced elsewhere.
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Rumex longifolius:
- pedicels with a distinct articulation point that is swollen and thicker the remaining pedicel, and inner tepals broad-orbicular to reniform, mostly 5–6 mm long (vs. R. occidentalis, with pedicels with an indistinct articulation point that is scarcely, if at all, thicker than the remaining pedicel, and inner tepals ovate or broad-ovate-triangular to suborbicular, mostly 5–10 mm long).
Synonyms
- Rumex aquaticus L. ssp. fenestratus (Greene) Hultén
- Rumex aquaticus L. ssp. occidentalis (S. Wats.) Hultén
- Rumex aquaticus L. var. fenestratus (Greene) Dorn
- Rumex fenestratus Greene
- Rumex occidentalis S. Wats. var. fenestratus (Greene) Lepage