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

Nuphar microphylla — small-leaved pond-lily

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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

Small-leaved pond-lily is found in much of New England, but is uncommon in some states. Ironically, broad-spectrum herbicides used to eradicate invasive aquatic weeds could be an important danger to this species where it occurs.

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
35–130 mm
Petal or sepal number
  • there are five petals, sepals, or tepals in the flower
  • there are seven or more petals, sepals, or tepals in the flower
Petal color
yellow
Specific leaf type
the leaf is not divided, rather the blade is made up of one segment
Floating leaf shape
the leaf blade is elliptic (widest near the middle and tapering at both ends)
Underwater leaf blade width
35–85 mm
Fruit type (general)
the fruit is fleshy
Underwater leaf length
35–130 mm
Show all characteristics

  • Clonal plantlets

    Turion length
    0 mm

  • Flowers

    Anther length
    1–3 mm
    Carpels fused
    the carpels are fused to one another
    Flower lower lip length
    0 mm
    Flower number
    1
    Flower position
    the flowers are above 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 has only one flower on it
    Inflorescence width
    10–20 mm
    Length of flower stalk
    0 mm
    Nectar spur
    the flower has no nectar spurs
    Number of carpels
    3–35
    Ovary position
    the sepals and/or petals are attached below the ovary
    Palate on corolla
    no
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal appearance
    NA
    Petal color
    yellow
    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
    At least 8
    Petal or sepal number
    • there are five petals, sepals, or tepals in the flower
    • there are seven or more petals, sepals, or tepals in the flower
    Pistil number
    1
    Sepal appearance
    the sepals resemble petals in color and texture
    Sepal length
    10–25 mm
    Sepal number
    5
    Sepals fused only to sepals
    the sepals are separate from one another
    Spur length
    0 mm
    Stamen number
    13 or more
    Stamen position relative to petals
    NA
    Stamens fused to petals
    the stamens are not fused to the petals or tepals
    Style length
    0 mm
    Style number
    0

  • Fruits or seeds

    Fruit length
    10–20 mm
    Fruit type (general)
    the fruit is fleshy
    Fruit type (specific)
    the fruit is a berry (fleshy, with the wall enclosing one or more sections, with two or more seeds)
    Fruit width
    2–5 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
    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
    yes
    Floating leaf blade width
    35–85 mm
    Floating leaf length
    35–100 mm
    Floating leaf shape
    the leaf blade is elliptic (widest near the middle and tapering at both ends)
    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
    NA
    Floral bract length
    0 mm
    Leaf arrangement
    alternate: there is one leaf per node along the stem
    Leaf blade length
    35–130 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
    35–85 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 blade edges
    the underwater leaf has smooth edges, without teeth
    Underwater leaf blade shape
    • the underwater leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the underwater leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    Underwater leaf blade width
    35–85 mm
    Underwater leaf length
    35–130 mm
    Underwater leaf stalk
    yes
    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 is upright
    • 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.

Connecticut
historical (S-rank: SH), special concern, extirpated (code: SC*)
Massachusetts
extremely rare (S-rank: S1), endangered (code: E)
New Hampshire
historical (S-rank: SH), endangered (code: E)

Native to North America?

Yes

Sometimes confused with

Nuphar advena:
sepals 2.5–5 cm long, numbering 6 per flower, anthers longer than the filaments, fruit only slightly constricted below the green or rarely red stigmatic disk, and basal sinus of leaf blade mostly 30–59 of the length of the blade midrib (vs. N. microphylla, with sepals 1–2.5 cm long, numbering 5 per flower, anthers predominantly shorter than the filaments, fruit strongly constricted below the red stigmatic disk, and basal sinus of leaf blade mostly 54–90% of the length of the blade midrib).

Synonyms

  • Nuphar minima (Willd.) Sm.
  • Nymphaea microphylla Pers.

Family

Nymphaeaceae

Genus

Nuphar

Help

From the dichotomous key of Flora Novae Angliae

2.  Nuphar microphylla (Pers.) Fern. N

small-leaved pond-lily. Nuphar minima (Willd.) Sm.; Nymphaea microphylla Pers. • CT, MA, ME, NH, VT; also reported for RI by Magee and Ahles (1999), but specimens are unknown. Circumneutral to basic water of lakes and slow-moving streams.

2×3. Nuphar microphylla × Nuphar variegata → Nuphar ×rubrodisca Morong is an infrequent hybrid of circumneutral to basic water. It is known from CT, MA, ME, NH, VT. It has been treated as a species, but it shows morphological intermediacy, poor fruit set, and lower pollen viability than other sympatric species (Padgett et al. 1998). It resembles N. microphylla in some key characteristics (e.g., short sepals, fruit constricted below stigmatic disk, anthers predominantly shorter than filaments). The hybrid is characterized by 5 or 6 sepals per flower, anthers (2–) 3–6 mm long, stigmatic disk with 8–15 stigmatic rays that terminate 0–1.6 mm from the margin, each ray separated by a shallow sinus, the constriction below the stigmatic disk 5–10 mm in diameter, petals and stamens usually persistent as remnants at the base of the fruit, and basal sinus of leaf blade 39–59 (–62)% of the length of the blade midrib (vs. sepals 5 per flower, anthers 1–3 mm long, stigmatic disk with 6–11 stigmatic rays that terminate 0–0.2 mm from the margin, each ray separated by a relatively deep sinus, the constriction below the stigmatic disk 1.5–5 mm in diameter, petals and stamens promptly deciduous, and basal sinus of leaf blade (42–) 54–90% in N. microphylla).