Sparganium angustifolium Michx.

narrow-leaved bur-reed

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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 About

Narrow-leaved bur-reed is a circumboreal species. It becomes rare in southern New England. True to its name it has narrow, flaccid leaves that are submerged or floating, rarely emersed. Compared to bur-reeds (Sparganium), it is not very variable' in appearance.

Habitat

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

Characteristics

Habitat
aquatic
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
Leaf position
  • some of the leaves are floating at the surface of the water
  • the leaves are all submerged underwater
Leaf arrangement
alternate: there is one leaf per node along the stem
Leaf blade length
200–2500 mm
Petal or sepal number
  • there are five petals, sepals, or tepals in the flower
  • there are four petals, sepals, or tepals in the flower
  • there are six petals, sepals, or tepals in the flower
  • there are three petals, sepals, or tepals in the flower
Petal color
  • brown
  • green
  • white
Specific leaf type
the leaf is not divided, rather the blade is made up of one segment
Floating leaf shape
the leaf blade is linear (very narrow with more or less parallel sides)
Underwater leaf blade width
2–10 mm
Fruit type (general)
the fruit is dry but does not split open when ripe
Underwater leaf length
200–2500 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
    Anther length
    0.8–1.2 mm
    Carpels fused
    the carpels are fused to one another
    Flower lower lip length
    0 mm
    Flower number
    3–23
    Flower position
    the flowers are floating on the surface of the water
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Inflorescence type
    the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)
    Length of flower stalk
    0 mm
    Length of peduncle
    0–85 mm
    Nectar spur
    the flower has no nectar spurs
    Number of carpels
    0–3
    Ovary position
    • NA
    • the sepals and/or petals are attached below the ovary
    Palate on corolla
    NA
    Petal and sepal arrangement
    • the flower includes only one cycle of petals or sepals
    • the flower includes two cycles of petal- or sepal-like structures
    Petal appearance
    NA
    Petal color
    • brown
    • green
    • white
    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 five petals, sepals, or tepals in the flower
    • there are four petals, sepals, or tepals in the flower
    • there are six petals, sepals, or tepals in the flower
    • 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 number
    3–6
    Sepals fused only to sepals
    the sepals are separate from one another
    Spur length
    0 mm
    Stamen number
    • 0
    • 1 or 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    Stamen position relative to petals
    NA
    Stamens fused
    • the stamens are fused to one another at or near their bases
    • 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
    0–1
  • Fruits or seeds
    Fruit beak length
    1.5–5 mm
    Fruit length
    3–7 mm
    Fruit type (general)
    the fruit is dry but does not split open when ripe
    Fruit type (specific)
    • the fruit is a drupe (fleshy, with a firm inner ovary wall that encloses a single seed)
    • the fruit is an achene (dry, usually 1-seeded, does not separate or split open at maturity)
    Fruit width
    1.2–1.7 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
    the plant has a rhizome (a horizontal underground stem with roots growing from it)
  • Leaves
    Bract position (Sparganium)
    the inflorescence bract is immediately below and touching the carpellate spikes and peduncles
    Bract relative length
    At least 1380 mm
    Bracts
    the flowers or their pedicels have bracts at their bases
    Floating leaf basal lobes
    no
    Floating leaf blade width
    2–10 mm
    Floating leaf length
    200–2500 mm
    Floating leaf shape
    the leaf blade is linear (very narrow with more or less parallel sides)
    Floating leaf tip
    • the tip of the floating leaf blade is obtuse (bluntly pointed)
    • the tip of the floating leaf blade is rounded, with no point
    Floral bract form
    the bracts are roughly as lobed as the foliage leaves
    Leaf arrangement
    alternate: there is one leaf per node along the stem
    Leaf blade length
    200–2500 mm
    Leaf blade veins
    the lateral veins are parallel or slightly arched in the direction of the tip
    Leaf blade width
    2–10 mm
    Leaf position
    • some of the leaves are floating at the surface of the water
    • 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
    there are no stipules on the plant
    Stipules fused around stem
    NA
    Trap-bladder length
    0 mm
    Underwater leaf air passage number
    At least 1440
    Underwater leaf blade edges
    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
    2–10 mm
    Underwater leaf length
    200–2500 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)
    • the tip of the underwater leaf is rounded, with no point
  • Place
    Habitat
    aquatic
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • 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

Distribution

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

Conservation Status

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

Massachusetts
rare to uncommon (S-rank: S2S3), #NAME? (code: #NAME?)

Native to North America?

Yes

Sometimes Confused With

Heteranthera dubia:
leaves thin, translucent, flat, and perianth yellow, conspicuous (vs. S. angustifolium, with leaves thicker, nearly opaque, flat to planoconvex, and perianth white to green, inconspicuous).

Synonyms

  • Sparganium emersum Rehmann var. angustifolium (Michx.) Taylor & MacBryde
  • Sparganium multipedunculatum (Morong) Rydb.

Family

Typhaceae

Genus

Sparganium

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Information from Dichotomous Key of Flora Novae Angliae

3.  Sparganium angustifolium Michx. N

narrow-leaved bur-reed. Sparganium emersum Rehmann var. angustifolium (Michx.) Taylor & MacBryde; S. multipedunculatum (Morong) Rydb. • CT, MA, ME, NH, VT; rare or absent from some southern New England states. Shallow, circumneutral to basic, still or slow-moving water. This species rarely somewhat emergent in shallow water.

3×4b.  This very rare bur-reed hybrid is known from NH, VT. It is intermediate in 
both vegetative and floral characters, and the F₁ individuals are known to be highly fertile. It has anthers 0.9–1.2 mm long and stigmas 0.8–1.4 (–1.7) mm, whereas Sparganium angustifolium has anthers (0.8–) 0.9–1 (–1.2) mm long and stigmas 
(0.6–) 0.8–1 (–1.2) mm long, and S. emersum has anthers 1–1.5 (–2) mm long and 
stigmas (1–) 1.5–2 (–2.5) mm long.