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• Dichotomous Key
• Poaceae
• Poaceae Group 8
• Setaria
• Setaria parviflora

Setaria parviflora — knotroot foxtail

Facts

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

• 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

From the dichotomous key of Flora Novae Angliae