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- Utricularia inflata
Utricularia inflata — swollen bladderwort
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Facts
Swollen bladderwort is native to southern and eastern North America, but it has been introduced in Massachusetts, as well as New York and the state of Washington. This species can be quite invasive, becoming dominant in ponds and displacing other native aquatic plants. It may be expected to continue expanding its range.
Habitat
Lacustrine (in lakes or ponds)
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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- Rhode Island
- Leaf position
- some of the leaves are floating at the surface of the water
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- whorled: there are three or more leaves per node along the stem
- Leaf blade length
- 20–100 mm
- Petal or sepal number
- there are five petals, sepals, or tepals in the flower
- Petal color
- yellow
- Specific leaf type
-
- the leaf has three or more lobes distributed along a central axis
- the leaf is divided into two equal parts, with five or more levels of division
- the leaf is pinnately compound (i.e., it has three or leaflets distributed along a central axis
- Floating leaf shape
-
- the leaf blade is linear (very narrow with more or less parallel sides)
- the leaf blade is oblong (rectangular but with rounded ends)
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Underwater leaf length
- 2–10 mm
-
Flowers
- Carpels fused
- the carpels are fused to one another
- Chasmogamous flowers
- absent
- Flower lower lip length
- 20–25 mm
- Flower number
- 4–17
- Flower position
- the flowers are above the surface of the water
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Inflorescence length
- 20–50 mm
- Inflorescence type
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- Length of flower stalk
- 10–35 mm
- Length of peduncle
- 10–30 mm
- Nectar spur
- the flower has nectar spurs
- Number of carpels
- 2
- Ovary position
- the sepals and/or petals are attached below the ovary
- Palate on corolla
- yes
- 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
- yellow
- Petal fringed edges
- the petals are not fringed
- Petal fusion
- the perianth parts are fused to form a tube, cup, or bell shape
- Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
- Petal length
- 20–25 mm
- Petal number
- 5
- Petal or sepal number
- there are five petals, sepals, or tepals in the flower
- Pistil number
- 1
- Sepal appearance
- the sepals resemble leaves in color and texture
- Sepal length
- 3–5 mm
- Sepal number
- 2
- Sepals fused only to sepals
- the sepals are fused to each other (not other flower parts), at least near their bases
- Stamen number
- 1 or 2
- Stamens fused
- the stamens are not fused to one another
- Stamens fused to petals
- the stamens are fused near the bases of the petals or tepals
- Style length
- At least 0 mm
-
Fruits or seeds
- Embryo coiling (Potamogeton)
- NA
- Fruit length
- 3–6 mm
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit type (specific)
- the fruit is a pyxis (when dry it splits around the middle, and the top falls off, exposing the seeds)
- Fruit width
- 3–6 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
- NA
- Roots floating in water
- there are no clusters of roots floating in the water
- Underground organs
- NA
-
Leaves
- Bract position (Sparganium)
- NA
- Bracts
- the flowers or their pedicels have bracts at their bases
- Floating leaf basal lobes
- no
- Floating leaf length
- 30–80 mm
- Floating leaf shape
-
- the leaf blade is linear (very narrow with more or less parallel sides)
- the leaf blade is oblong (rectangular but with rounded ends)
- Floral bract form
- the bracts are much more lobed, or much less lobed, than the foliage leaves
- Floral bract length
- 3–7 mm
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- whorled: there are three or more leaves per node along the stem
- Leaf blade length
- 20–100 mm
- Leaf position
- some of the leaves are floating at the surface of the water
- Leaf special features
-
- the leaves have bladder-like traps
- the leaves have inflated petioles or blades that help them float
- Leaf-like branch shape
- the leaf-like branches are round
- Specific leaf type
-
- the leaf has three or more lobes distributed along a central axis
- the leaf is divided into two equal parts, with five or more levels of division
- the leaf is pinnately compound (i.e., it has three or leaflets distributed along a central axis
- 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
- 1–3 mm
- Underwater leaf blade edges
- the underwater leaf has tiny, one-celled spines or points along the edge
- Underwater leaf blade shape
-
- NA
- the underwater leaf blade is obovate (egg-shaped, but with the widest point above the middle of the underwater leaf blade)
- the underwater leaf blade is orbicular (roughly circular, as wide as long)
- the underwater leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Underwater leaf length
- 2–10 mm
- Underwater leaf stalk
- no
- Underwater leaf tip shape
- the tip of the underwater leaf is truncate (ends abruptly in a more or less straight line as though cut off)
-
Place
- Habitat
-
- aquatic
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- Rhode Island
- Specific habitat
- in lakes or ponds
-
Stem, shoot, branch
- Flowering stem growth form
- the flowering stem trails along the substrate, or floats in the water
Wetland status
Not classified
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- present
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- not applicable (S-rank: SNA)
From Flora Novae Angliae dichotomous key
4. Utricularia inflata Walt. E
swollen bladderwort. Plectoma inflata (Walt.) Raf.; Utricularia ceratophylla Michx. • CT, MA, ME. Shallow water of ponds.
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Utricularia radiata:
- raceme with mostly 1-5 flowers, peduncle above the inflated branches 3-10 cm long, inflated branches 10-40 mm long bearing branches only near the apex, and sepals 2.5-3.5 mm long (vs. U. inflata, with raceme with mostly 9–14 flowers, peduncle above the inflated branches 10-30 cm, inflated branches 30-80 mm long bearing branches in the distal half, and sepals 3-5 mm long).
Synonyms
- Plectoma inflata (Walt.) Raf.
- Utricularia ceratophylla Michx.