• You are here:
• Simple Key
• Aquatic plants
• Water plants with leaves and stems
• Vallisneria americana

Vallisneria americana — American eelgrass, tape-grass

Facts

Tape-grass is found throughout New England in lakes and slow-moving rivers in neutral to basic water. It is such an important food to canvasback ducks that it has been known to affect their migration patterns. It is also eaten by many other waterbirds. After the flowers are fertilized, the flower stalk coils downwards and pulls the fruit underwater.

Habitat

Lacustrine (in lakes or ponds), riverine (in rivers or streams)

Characteristics

• Flowers

  Carpels fused

  the carpels are fused to one another

  Flower lower lip length

  0 mm

  Flower number

  At least 1

  Flower position

  • the flowers are below the surface of the water
  • the flowers are floating on the surface of the water

  Flower symmetry

  there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)

  Inflorescence type

  • the inflorescence has only one flower on it
  • the inflorescence is a monochasial cyme (an axis with a terminal flower, below it a branch with a terminal flower, this branch may itself have a branch and so on)

  Inflorescence width

  1–1.5 mm

  Length of flower stalk

  At least 0 mm

  Length of peduncle

  30–50 mm

  Nectar spur

  the flower has no nectar spurs

  Number of carpels

  0–6

  Ovary position

  the sepals and/or petals are attached above the ovary

  Palate on corolla

  no

  Petal and sepal arrangement

  the flower includes two cycles of petal- or sepal-like structures

  Petal appearance

  the petals are thin and delicate, and pigmented (colored other than green or brown)

  Petal color

  white

  Petal fringed edges

  the petals are not fringed

  Petal fusion

  the perianth parts are separate

  Petal hairs on inner/upper surface

  there are no hairs on the inner/upper petal surface

  Petal number

  1–3

  Petal or sepal number

  there are three petals, sepals, or tepals in the flower

  Pistil number

  • 0
  • 1

  Sepal appearance

  the sepals resemble leaves in color and texture

  Sepal length

  3.5–6.5 mm

  Sepal number

  3

  Sepals fused only to sepals

  the sepals are separate from one another

  Spur length

  0 mm

  Stamen number

  • 0
  • 1 or 2

  Stamen position relative to petals

  NA

  Stamens fused

  the stamens are fused to one another at or near their bases

  Stamens fused to petals

  the stamens are not fused to the petals or tepals

  Style number

  0–1

• Fruits or seeds

  Fruit beak length

  0 mm

  Fruit length

  50–120 mm

  Fruit type (general)

  the fruit is dry and splits open when ripe

  Fruit type (specific)

  the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)

• Glands or sap

  Oil glands on nodes

  none of the nodes have oil glands

  Sap

  the sap is clear and watery

• Growth form

  Lifespan

  the plant lives more than two years

  Root septa

  the roots do not have transverse septa

  Roots floating in water

  there are no clusters of roots floating in the water

  Turions

  the plant has turions

  Underground organs

  the plant has a rhizome (a horizontal underground stem with roots growing from it)

• Leaves

  Bract position (Sparganium)

  NA

  Bract relative length

  At least 3854 mm

  Bracts

  neither the flowers nor their pedicels have bracts

  Floating leaf basal lobes

  NA

  Floating leaf blade width

  0 mm

  Floating leaf length

  0 mm

  Floating leaf shape

  NA

  Floating leaf tip

  NA

  Floral bract form

  NA

  Floral bract length

  0 mm

  Leaf arrangement

  basal: the leaves are growing only at the base of the plant

  Leaf blade length

  100–1100 mm

  Leaf blade veins

  the lateral veins are parallel or slightly arched in the direction of the tip

  Leaf blade width

  3–15 mm

  Leaf position

  the leaves are all submerged underwater

  Leaf special features

  none of the mentioned special features are present

  Leaf-like branch segments

  0

  Leaf-like branch shape

  NA

  Specific leaf type

  the leaf is not divided, rather the blade is made up of one segment

  Staminate bract edge (Myriophyllum)

  NA

  Stipule appearance

  NA

  Stipule fused to leaf

  NA

  Stipules

  the plant has stipules

  Stipules fused around stem

  NA

  Trap-bladder length

  0 mm

  Underwater leaf air passage number

  At least 1440

  Underwater leaf air passage relative width

  At least 1441

  Underwater leaf air passage row number

  4–5

  Underwater leaf blade edges

  • the underwater leaf blade edges are toothed
  • the underwater leaf has smooth edges, without teeth

  Underwater leaf blade shape

  the underwater leaf blade is linear (very narrow with more or less parallel sides)

  Underwater leaf blade width

  3–15 mm

  Underwater leaf length

  100–1100 mm

  Underwater leaf stalk

  no

  Underwater leaf stalk length

  0 mm

  Underwater leaf tip shape

  the tip of the underwater leaf is obtuse (bluntly pointed)

  Veins in floating leaf

  0

• Place

  Habitat

  aquatic

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • in lakes or ponds
  • in rivers or streams

• Stem, shoot, branch

  Flowering stem growth form

  the flowering stem trails along the substrate, or floats in the water

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae