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Native Plant Trust: Go Botany Discover thousands of New England plants

Ruppia maritima — beaked ditch-grass, widgeongrass

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New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Facts

Beaked ditch-grass can tolerate a wide range of salinities, from brackish water to sea-water. It is highly nutritous and an important food plant for waterfowl.

Habitat

Lacustrine (in lakes or ponds), intertidal, subtidal or open ocean, riverine (in rivers or streams)

Characteristics

Habitat
  • aquatic
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
Leaf position
the leaves are all submerged underwater
Leaf arrangement
alternate: there is one leaf per node along the stem
Leaf blade length
60–105 mm
Petal or sepal number
there are no petals, sepals, or tepals in the flower, or they are not clearly present
Petal color
NA
Specific leaf type
the leaf is not divided, rather the blade is made up of one segment
Floating leaf shape
NA
Underwater leaf blade width
0.3–0.5 mm
Fruit type (general)
the fruit is fleshy
Underwater leaf length
60–105 mm
Show all characteristics

  • Clonal plantlets

    Turion length
    0 mm

  • Flowers

    Anther color
    there is a noticeable pink, reddish or purplish tint to the anthers
    Carpels fused
    the carpel is solitary or (if 2 or more) the carpels are not fused to one another
    Flower lower lip length
    0 mm
    Flower number
    2–20
    Flower position
    the flowers are below the surface of the water
    Flower symmetry
    NA
    Inflorescence type
    the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)
    Length of peduncle
    0.5–16.5 mm
    Nectar spur
    the flower has no nectar spurs
    Number of carpels
    4
    Ovary position
    NA
    Palate on corolla
    NA
    Petal and sepal arrangement
    the flower includes neither petals nor sepals
    Petal appearance
    NA
    Petal color
    NA
    Petal fringed edges
    NA
    Petal fusion
    NA
    Petal hairs on inner/upper surface
    NA
    Petal length
    0 mm
    Petal number
    0
    Petal or sepal number
    there are no petals, sepals, or tepals in the flower, or they are not clearly present
    Pistil number
    • 4
    • 5
    • 6 or more
    Sepal appearance
    NA
    Sepal length
    0 mm
    Sepal number
    0
    Sepals fused only to sepals
    NA
    Spur length
    0 mm
    Stamen number
    1 or 2
    Stamen position relative to petals
    NA
    Stamens fused
    the stamens are not fused to one another
    Stamens fused to petals
    • NA
    • the stamens are not fused to the petals or tepals
    Style number
    4–8

  • Fruits or seeds

    Fruit beak length
    0.6–1 mm
    Fruit length
    1.8–2 mm
    Fruit type (general)
    the fruit is fleshy
    Fruit type (specific)
    the fruit is a drupe (fleshy, with a firm inner ovary wall that encloses a single seed)
    Fruit width
    0.7–1.5 mm

  • 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
    there are no turions on the plant
    Underground organs
    there are only slender roots on the plant

  • 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
    alternate: there is one leaf per node along the stem
    Leaf blade length
    60–105 mm
    Leaf blade veins
    the lateral veins radiate from the base and continue to spread away from the centerline of the leaf, or branch off the central vein at intervals
    Leaf blade width
    0.3–0.5 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
    the stipules are delicate and translucent
    Stipule fused to leaf
    the stipules are attached to the leaf blade for some part of their length
    Stipules
    the plant has stipules
    Stipules fused around stem
    the stipules do not forma closed tube around the stem
    Trap-bladder length
    0 mm
    Underwater leaf blade edges
    the underwater leaf blade edges are toothed
    Underwater leaf blade shape
    the underwater leaf blade is linear (very narrow with more or less parallel sides)
    Underwater leaf blade veins
    1
    Underwater leaf blade width
    0.3–0.5 mm
    Underwater leaf length
    60–105 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
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    Specific habitat
    • in lakes or ponds
    • in rivers or streams
    • intertidal, subtidal or open ocean

  • 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

Distribution

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

Conservation status

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

Maine
unranked (S-rank: SNR)
Massachusetts
fairly widespread (S-rank: S4S5)

Native to North America?

Yes

Sometimes confused with

Zannichellia palustris:
leaves opposite, mature fruits borne on stalks 0.3-1.2 mm long, and stigma funnelform (vs. R. maritima, with leaves alternate to subopposite, mature fruits borne on stalks 12-19 mm long, and stigma capitate).

Synonyms

  • Ruppia maritima var. longipes Hagstr.
  • Ruppia maritima var. obliqua (Schur) Aschers. & Graebn.
  • Ruppia maritima var. rostrata Agardh
  • Ruppia maritima var. subcapitata Fern. & Wieg.

Family

Ruppiaceae

Genus

Ruppia

Help

From the dichotomous key of Flora Novae Angliae

1.  Ruppia maritima L. N

beaked ditch-grass. Ruppia maritima L. var. longipes Hagstr.; R. maritima L. var. obliqua (Schur) Aschers. & Graebn.; R. maritima L. var. rostrata Agardh; R. maritima L. var. subcapitata Fern. & Wieg. • CT, MA, ME, NH, RI; also reported from VT by Magee and Ahles (1999), but specimens are unknown. Saline to brackish waters and pools.