Bolboschoenus glaucus (Lam.) S.G. Smith

glaucous tuber-bulrush

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

New England Distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America Distribution

Adapted from BONAP data

enlarge

Facts About

Glaucous tuber-bulrush, native to Eurasia, was unintentionally introduced to a human-made wetland in New Hampshire, when misidentified rootstock was planted.

Habitat

Marshes, shores of rivers or lakes

Characteristics

Habitat
  • aquatic
  • wetlands
New England state
New Hampshire
Stem shape in cross-section
the stem is roughly triangular in cross-section
Leaf blade width
2–6 mm
Leaf blade cross-section
the leaf blade is flat or rolled in at the edges
Inflorescence position
the inflorescence is at the tip of the plant
Inflorescence branching
the inflorescence is branched
Fruit type (general)
the fruit is like a seed, and surrounded by scales
Fruit length
2.5–3.3 mm
Leaf position on plant
  • some leaf attachment points are above the midpoint of the stem
  • the attachment points of all the leaves are at or near the base of the plant
Perianth composition
there are bristles attached at the base of the achene
Fruit cross-section
  • the fruit is biconvex or elliptic (widest in the middle and tapering to both ends) in cross-section
  • the fruit is triangular to terete (circular) in cross-section
Show All Characteristics
  • Flowers
    Anther color (dry)
    the anthers range in color from white to tan or yellow to yellow-brown
    Anther length
    3 mm
    Floral bristle color
    the bristles are pale brown to brown
    Floral bristle number
    • 1-4
    • 5-7
    Floral bristle relative length
    the bristles are between one tenth as long as the achene, and equal in length to the achene
    Floral bristles
    the bristles are straight or slightly curved
    Floral scale hairs
    the floral scales have hairs on them
    Floral scale length
    5–6 mm
    Floral scale nerves
    1
    Floral scale shape
    • the floral scales are ovate (roughly egg-shaped)
    • the floral scales are triangular
    Floral scale translucent
    the floral scales are translucent
    Inflorescence bract angle
    the bracts are vertical or angled only slightly outwards
    Inflorescence bract number
    • there are two to five bracts per inflorescence
    • there is just one bract on the inflorescence
    Inflorescence bract position (Sparganium)
    NA
    Inflorescence bracts
    there are at least two bracts, and they are either flat or folded or rolled in at the edges
    Inflorescence branching
    the inflorescence is branched
    Inflorescence crowding
    the inflorescence is at least somewhat spread out, with at least one branch coming from the main stem
    Inflorescence position
    the inflorescence is at the tip of the plant
    Inflorescence shape
    the aggregations within the inflorescence are roughly circular (not flattened) in cross-section
    Inflorescence type
    there are two or more flowers, spikes or flower clusters on a branched inflorescence
    Perianth composition
    there are bristles attached at the base of the achene
    Stamen number
    3
    Stigma number
    • 2
    • 3
    Style division
    the top two thirds of the style is divided
    floral bristle barbs
    the bristles have tiny barbs on them
    plantlets budding at flower bases
    no
  • Fruits or seeds
    Achene surface texture
    the achene is smooth (it has no detectable texture)
    Achene tubercle relative width
    NA
    Achene tubercle width
    0 mm
    Capsule relative length
    NA
    Fruit cross-section
    • the fruit is biconvex or elliptic (widest in the middle and tapering to both ends) in cross-section
    • the fruit is triangular to terete (circular) in cross-section
    Fruit length
    2.5–3.3 mm
    Fruit type (general)
    the fruit is like a seed, and surrounded by scales
    Fruit type (specific)
    the fruit is an achene (dry, seed-like fruit) without a tubercle (a swelling or projection, usually of a different color or texture)
    Locules in capsule
    NA
    Seed length
    0 mm
    Seed tail relative length
    0 mm
    Seed tails
    NA
    Tubercle height
    0 mm
  • Growth form
    Lifespan
    the plant lives more than two years
    Underground organs
    • the plant has a rhizome (a horizontal underground stem with roots growing from it)
    • the plant has one or more swollen storage organs underground, such as bulbs or tubers
  • Leaves
    Auricle length
    0 mm
    Auricle texture
    NA
    Auricles
    there are no auricles on the leaf sheath
    Leaf blade cross-section
    the leaf blade is flat or rolled in at the edges
    Leaf blade width
    2–6 mm
    Leaf form
    all the leaves hold their form out of water
    Leaf position on plant
    • some leaf attachment points are above the midpoint of the stem
    • the attachment points of all the leaves are at or near the base of the plant
    Leaf septa
    the leaf blades do not have transverse septa
    Leaf sheath hairs
    the leaf sheathes are without hairs
    Pedicel length (Typha)
    0 mm
    Stem leaf blade ligules
    there are no ligules at the leaf blade bases
    Stem leaf blades
    there are fully-developed leaves with leaf blades on the main stem
  • Place
    Habitat
    • aquatic
    • wetlands
    New England state
    New Hampshire
    Specific habitat
    • marshes
    • shores of rivers or lakes
  • Stem, shoot, branch
    Plant height
    30–150 cm
    Stem shape in cross-section
    the stem is roughly triangular in cross-section
    Stem texture near tip
    the stem feels smooth near the tip

Wetland Status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England Distribution and Conservation Status

Distribution

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

Conservation Status

None

Native to North America?

No

Sometimes Confused With

Bolboschoenus fluviatilis:
widest leaf blades 7-22 mm wide, spikelets mostly 5-10 mm in diameter, and achenes 3.8-5.5 mm long with an evident style beak 0.1-0.8 mm long (vs. B. glaucus, with the widest leave blades 7-22 mm wide, spikelets mostly 3-5 mm wide, and achenes 2.5-3.3 mm long with a minute style beak).

Synonyms

  • Schoenoplectus glaucus (Lam.) Kartesz
  • Scirpus glaucus Lam.

Family

Cyperaceae

Need Help?

Get Help

Information from Dichotomous Key of Flora Novae Angliae

2.  Bolboschoenus glaucus (Lam.) S.G. Smith E

glaucous tuber-bulrush. Schoenoplectus glaucus (Lam.) Kartesz; Scirpus glaucus Lam. 
• NH. Marshes, shorelines. Unintentionally introduced into a human-made wetland 
when it was purchased under the name of another tuberous bulrush (i.e., the plant stock 
was misidentified).