Setaria parviflora (Poir.) Kerguélen

knotroot foxtail

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

Knotroot foxtail is native to much of North America, but at the northern limit of its range in New England. In our region it is an uncommon inhabitant of the margins of salt marshes and disturbed areas near the coast.

Habitat

Anthropogenic (man-made or disturbed habitats), marshes, wetland margins (edges of wetlands)

Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Massachusetts
  • Rhode Island
Leaf blade width
2–8 mm
Inflorescence branches
  • the flowers are attached to branches rather than to the main axis of the inflorescence
  • there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
Spikelet length
2–2.8 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
0.4–1.2 mm
Anther length
1.2–1.6 mm
Show All Characteristics
  • Flowers
    Anther length
    1.2–1.6 mm
    Anther number
    Up to 3
    Awn on glume
    the glume has no awn
    Bristles below spikelets
    yes
    Floret lower bract texture
    the lemma is hard and firm
    Floret number
    1–2
    Floret types within spikelet
    • NA
    • there are at least two distinct forms of florets within one spikelet
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume shape
    the glume is flat or curved in cross-section
    Glume veins
    • 3
    • 5
    • 7 or more
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis hairs
    the inflorescence axis is hairy but not rough or sand-papery feeling
    Inflorescence axis orientation
    • the inflorescence axis is arched or curved outward
    • the inflorescence axis is straight
    Inflorescence branches
    • the flowers are attached to branches rather than to the main axis of the inflorescence
    • there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
    Inflorescence crowding
    the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    Inflorescence length
    30–100 mm
    Inflorescence type (general)
    • the inflorescence is a spike, or is spike-like, lacking obvious branches
    • the spikelets are borne on stalks or on branches
    Inflorescence type (specific)
    the inflorescence is branched, and the branches do NOT both 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 length
    0 mm
    Lemma awn number
    the lemma has no awn
    Lemma cross-section
    the lemma is flat or rounded if you cut across the midpoint
    Lemma surface
    the surface of the lemma has wrinkles that are oriented across the lemma
    Lemma tip
    the lemma tip is a simple point, with or without an awn (long narrow extension ending in a point)
    Lemma vein number
    • 1
    • 3
    • 5
    One or more florets
    • there is more than one floret per spikelet
    • there is one floret per spikelet
    Palea relative length
    palea is one half to fully as long as lemma
    Spikelet axis tip
    there is an extension of the spikelet axis beyond the tip of the spikelet
    Spikelet length
    2–2.8 mm
    Spikelets spiny
    the spikelets do not appear spiny
  • Growth form
    Lifespan
    the plant lives more than two years
    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 width
    2–8 mm
    Leaf ligule length
    0.4–1.2 mm
    Leaf ligule type
    the leaf ligule is in the form of fine hairs
    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
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Massachusetts
    • Rhode Island
    Specific habitat
    • edges of wetlands
    • man-made or disturbed habitats
    • marshes
  • Stem, shoot, branch
    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland Status

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

New England Distribution and Conservation Status

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
uncommon (S-rank: S3), special concern (code: SC)
Rhode Island
extremely rare (S-rank: S1), concern (uncertain) (code: C*)

Native to North America?

Yes

Sometimes Confused With

Setaria pumila

Synonyms

  • Panicum geniculatum Lam.
  • Setaria geniculata (Lam.) Beauv.

Family

Poaceae

Genus

Setaria

Need Help?

Get Help

Information from Dichotomous Key of Flora Novae Angliae

3.  Setaria parviflora (Poir.) Kerguélen N

knotroot foxtail. Panicum geniculatum Lam.; Setaria geniculata (Lam.) Beauv. • CT, MA, RI. Borders of saline marshes, disturbed soil.