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Beckmannia syzigachne — American slough grass

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Facts

American slough grass is a wetland annual grass native to Asia, and to the western and northern United States, but not to New England. It has been collected in Connecticut and Massachusetts. The specific name (syzigachne) is derived from Greek and means "jointed achene".

Habitat

Anthropogenic (man-made or disturbed habitats), marshes, meadows and fields, shores of rivers or lakes, swamps, wetland margins (edges of wetlands)

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
wetlands
New England state
  • Connecticut
  • Maine
  • Vermont
Leaf blade width
4–20 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
2–3 mm
Glume relative length
neither glume is quite as long as all of the florets
Awn on glume
the glume has no awn
One or more florets
  • there is more than one floret per spikelet
  • there is one floret per spikelet
Lemma awn length
0 mm
Leaf sheath hair type
there are no hairs on the surface of the leaf sheath
Leaf ligule length
5–11 mm
Anther length
0.5–1.5 mm
Show all characteristics
  • Flowers

    Anther length
    0.5–1.5 mm
    Anther number
    3
    Awn on glume
    the glume has no awn
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is thin and flexible
    Floret number
    1–2
    Floret types within spikelet
    all the florets within a spikelet are similar
    Glume awn length
    0 mm
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume shape
    the glume is V-shaped in cross-section
    Glume veins
    3
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branch length
    1–2 cm
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence crowding
    the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    Inflorescence length
    70–300 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
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn base
    NA
    Lemma awn coiled
    NA
    Lemma awn length
    0 mm
    Lemma awn number
    the lemma has no awn
    Lemma awn orientation
    NA
    Lemma base hair length
    0 mm
    Lemma base hairs
    the lemma is hairless or feels just a tiny bit rough at the base
    Lemma cross-section
    the lemma is flat or rounded if you cut across the midpoint
    Lemma hairs
    the lemma is hairless between the veins
    Lemma keel hairs
    NA
    Lemma surface
    the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)
    Lemma tip
    the lemma tip is a simple point, with or without an awn (long narrow extension ending in a point)
    Lemma tip shape
    the lemma tip tapers to a long narrow point (it may or may not also have an awn or teeth at the tip)
    Lemma vein number
    5
    Lower glume length
    3–3.5 mm
    Lower glume relative length
    the lower glume is nearly as long, or as long as, the upper glume
    One or more florets
    • there is more than one floret per spikelet
    • there is one floret per spikelet
    Palea length
    2.4–3.5 mm
    Palea relative length
    palea is one half to fully as long as lemma
    Reproductive system
    all the flowers on the plant have both carpels and stamens (synoecious)
    Spikelet axis tip
    there is no extension of the spikelet axis beyond the tip of the spikelet
    Spikelet disintegration
    the spikelet breaks off below the glumes
    Spikelet length
    2–3 mm
    Spikelet number per node
    0
    Spikelet pedicel
    • the spikelets do not have pedicels
    • the spikelets have pedicels
    Spikelet pedicel length
    At least 0 mm
    Spikelet position
    the spikelets emerge from both the upper and lower halves of the inflorescence branches
    Spikelet shape
    • the spikelets are orbicular (circular) in profile
    • the spikelets are ovate (egg-shaped, widest below the middle with rounded ends) in profile
    Spikelets spiny
    the spikelets do not appear spiny
    Tip of glume
    the tip of the glume is not divided (though it may have an awn on it)
    Upper glume length
    3–3.5 mm
    Upper glume relative length
    the upper glume is more than one half as long as the lowest lemma
    Upper glume shape
    the upper glume is widest above the middle
  • Fruits or seeds

    Seed length
    Up to 2 mm
  • Growth form

    Horizontal rooting stem
    no
    Lifespan
    the plant lives only a single year or less
    Rhizomes
    no
    Roots
    there are only slender roots on the plant
  • Leaves

    Basal leaves
    the plant has few or no leaves coming from the base of the flowering stem
    Leaf auricles
    the leaves do not have auricles
    Leaf basal lobe hairy
    NA
    Leaf blade base
    the leaf is tapered gradually to the base
    Leaf blade cross-section
    the leaf blade is more or less flat in cross-section, or slightly folded or rolled inwards
    Leaf blade hairs
    the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
    Leaf blade length
    10–25 cm
    Leaf blade texture
    the leaf blade is rough and sandpapery
    Leaf blade width
    4–20 mm
    Leaf ligule length
    5–11 mm
    Leaf ligule type
    the leaf ligule is in the form of a membrane
    Leaf margin glands
    there are no glands along the edges of the leaf blade
    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 hair type
    there are no hairs on the surface of the leaf sheath
    Leaf sheath hairs
    there are no hairs on the surface of the leaf sheath
    Orientation of topmost leaf
    the flag leaf is held upright, or at less than a 45 degree angle out from the stem
  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Maine
    • Vermont
    Specific habitat
    • edges of wetlands
    • man-made or disturbed habitats
    • marshes
    • meadows or fields
    • shores of rivers or lakes
    • swamps
  • Stem, shoot, branch

    Plant height
    20–120 cm
    Roots at lower stem nodes
    no
    Stem node number
    2–4
    Stem orientation
    the stems are upright
    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland status

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

In New England

Distribution

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

Conservation status

None

From Flora Novae Angliae dichotomous key

1.  Beckmannia syzigachne (Steud.) Fern. E

American slough grass. Beckmannia erucaeformis (L.) Host ssp. syzigachne (Steud.) 
Breitung; Panicum syzigachne Steud. • CT, ME, VT. Wet ditches, low meadows, shorelines, marshes, edges of swamps.

Native to North America?

Yes and no (some introduced)

Sometimes confused with

Leptochloa fusca:
spikelets clearly longer than wide, with 2-20 bisexual florets, and glumes not cross-wrinkled, their tips separate (vs. B. syzigachne, with spikelets nearly circular in outline, with 1 floret or 2 florets and then the upper one sterile, and glumes cross-wrinkled, their tips crossing).

Synonyms

  • Beckmannia erucaeformis (L.) Host ssp. syzigachne (Steud.) Breitung
  • Panicum syzigachne Steud.

Family

Poaceae

Genus

Beckmannia