Justicia americana — American water-willow
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Facts
American water-willow is very rare in New England, where it is known only from Vermont. Elsewhere in North America it is a common and widespread perennial that forms large colonies in shallow water of lakes, ponds, and streams. Research has shown that it provides important shallow-water refuge for young fresh-water fishes. Despite its common name it is not a woody plant and not closely related to the willows (Salix).
Habitat
Marshes, 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.
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enlargeCharacteristics
- Habitat
- wetlands
- New England state
- Vermont
- Flower petal color
-
- pink to red
- white
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- opposite: there are two leaves per node along the stem
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Stamen number
- 1 or 2
- Fruit type (general)
- the fruit is dry and splits open when ripe
-
Clonal plantlets
- Bulbils
- the plant does not appear to have bulbils
- Bulblets replace flowers
- there are no bulblets where the flowers are located
-
Flowers
- 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 morphology
- the flower has two prominent lips
- Corolla palate
-
- no
- yes
- Corona lobe length
- 0 mm
- Epicalyx
- the flower does not have an epicalyx
- Epicalyx number of parts
- 0
- Flower description
- the flower has a superior ovary, and lacks a hypanthium
- Flower petal color
-
- pink to red
- white
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Flowers sunken into stem
- no
- 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
- 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
-
- 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 hairs (Viola)
- NA
- Petal number
- 5
- Petal tip shape
-
- the petal tip is obtuse (bluntly pointed)
- the petal tip is rounded
- the petal tip is truncate (ends abruptly in a more or less straight line as though cut off)
- Petal tips (Cuscuta)
- NA
- Scales inside corolla
- no
- Sepal and petal color
- NA
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Stamen number
- 1 or 2
- Umbel flower reproductive parts
- 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
- Fruit (pyxis) dehiscence
- NA
- Fruit features (Brassicaceae)
- NA
- Fruit locules
- two
- Fruit type (general)
- the fruit is dry and splits 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
- 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
- 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
- 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
- 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
- opposite: there are two leaves 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
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade length
- 80–16 mm
- Leaf blade shape
-
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is linear (very narrow with more or less parallel sides)
- the leaf blade is oblong (rectangular but with rounded ends)
- Leaf blade surface colors
- 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 green, with an expanded blade and a leaf-like texture
- Leaf spines
- there are no spines on the leaf edges
- 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)
- Leaflet number
- 0
- Leaflet petiolules
- NA
- Leaves per node
- there are two leaves 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
- NA
- Stipules
- there are no stipules on the plant
-
Place
- Habitat
- wetlands
- New England state
- Vermont
- Specific habitat
-
- edges of wetlands
- marshes
- shores of rivers or lakes
- swamps
-
Stem, shoot, branch
- Branched tendrils
- NA
- Hairs between stem nodes
- the stem has no hairs between the nodes
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Plant height
- 50–100 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
- absent
- Massachusetts
- absent
- 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.
- Vermont
- extirpated (S-rank: SX)
From Flora Novae Angliae dichotomous key
1. Justicia americana (L.) Vahl NC
American water-willow. Dianthera americana L. • VT. River and lake shores, backwater sloughs, swamp margins.