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- Sparganium angustifolium
Sparganium angustifolium — narrow-leaved bur-reed
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Facts
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)
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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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
-
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)
In New England
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)
From Flora Novae Angliae dichotomous key
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.
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).
- Sparganium emersum:
- distal portion of leaves with a prominent abaxial keel or triangular in cross-section, beak of fruit 2–4.5 mm long, and at least some of the staminate spikes separated by short internodes (vs. S. angustifolium, with distal portion of leaves flat, without an abaxial keel, beak of fruit mostly 1.5–2 mm long, and staminate spikes contiguous).
Synonyms
- Sparganium emersum Rehmann var. angustifolium (Michx.) Taylor & MacBryde
- Sparganium multipedunculatum (Morong) Rydb.