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Spartina cynosuroides — big cordgrass

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Facts

Big cordgrass is a saltmarsh and brackish marsh grass found on the coasts of Connecticut, Massachusetts and Rhode Island, as well as south to the Gulf Coast. It is a highly productive plant that contributes detritus to the tidal wetlands, helping to make them fertile nursery habitat for many fish species.

Habitat

Brackish or salt marshes and flats, marshes

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
  • aquatic
  • wetlands
New England state
  • Connecticut
  • Massachusetts
  • Rhode Island
Leaf blade width
6–20 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
9–14 mm
Glume relative length
neither glume is quite as long as all of the florets
Awn on glume
the glume has an awn
One or more florets
there is one floret per spikelet
Lemma awn length
0 mm
Leaf ligule length
1–3 mm
Anther length
4–6 mm
Show all characteristics

  • Flowers

    Anther length
    4–6 mm
    Anther number
    3
    Awn on glume
    the glume has an awn
    Floret lower bract texture
    the lemma is thin and flexible
    Floret number
    1
    Glume awn length
    Up to 2 mm
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume veins
    • 1
    • 3
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence length
    150–400 mm
    Inflorescence type (general)
    the spikelets are borne on stalks or on branches
    Inflorescence type (specific)
    the inflorescence is branched and the branches all grow from the same side of the plant and look like spikes
    Lemma awn base
    NA
    Lemma awn length
    0 mm
    Lemma awn number
    the lemma has no awn
    Lemma cross-section
    the lemma is V-shaped if you cut across the midpoint
    Lemma surface
    the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)
    Lemma vein number
    • 1
    • 3
    One or more florets
    there is one floret per spikelet
    Palea relative length
    palea is longer than lemma
    Spikelet axis tip
    there is no extension of the spikelet axis beyond the tip of the spikelet
    Spikelet length
    9–14 mm
    Spikelets spiny
    the spikelets do not appear spiny

  • Growth form

    Horizontal rooting stem
    no
    Rhizomes
    yes
    Roots
    the plant has rhizomes (horizontal underground stem with roots growing from it)

  • Leaves

    Leaf auricles
    the leaves do not have auricles
    Leaf blade hairs
    the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
    Leaf blade width
    6–20 mm
    Leaf ligule length
    1–3 mm
    Leaf ligule type
    the leaf ligule is in the form of a membrane with fine hairs
    Leaf sheath closed around stem
    the margins of the leaf sheath are overlapping and not fused together except in the basal half (or less)
    Leaf sheath hairs
    • there are hairs on the surface of the leaf sheath
    • there are no hairs on the surface of the leaf sheath

  • Place

    Habitat
    • aquatic
    • wetlands
    New England state
    • Connecticut
    • Massachusetts
    • Rhode Island
    Specific habitat
    • brackish or salt marshes and flats
    • marshes

  • Stem, shoot, branch

    Stem spacing
    • the stems grow close together in compact clusters or tufts
    • the stems grow singly or a few together (they may form diffuse colonies)

Wetland status

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

In New England

Distribution

Connecticut
present
Maine
absent
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
rare (S-rank: S2), threatened (code: T)
Rhode Island
extremely rare (S-rank: S1), concern (code: C)

From Flora Novae Angliae dichotomous key

2.  Spartina cynosuroides (L.) Roth NC

big cordgrass. Spartina cynosuroides (L.) Roth var. polystachya (Michx.) Beal ex Fern.; 
 S. polystachya Michx. • CT, MA, RI. Saline and brackish marshes.

Native to North America?

Yes

Sometimes confused with

Spartina pectinata:
upper glumes with awns 3–8 mm long, the lateral veins usually glabrous, and lower glume 3/4 to fully as long as adjacent lemma (vs. S. cynosuroides, upper glumes unawned or with awns up to 2 mm long, the lateral veins usually hispid, and lower glume 1/2 to 2/3 as long as adjacent lemma).

Synonyms

  • Spartina cynosuroides (L.) Roth var. polystachya (Michx.) Beal ex Fern.
  • Spartina polystachya Michx.

Family

Poaceae

Genus

Spartina