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• Justicia americana

Justicia americana — American water-willow

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)

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

  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 (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 (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)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae