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• Dichotomous Key
• Poaceae
• Poaceae Group 10
• Dichanthelium
• Dichanthelium dichotomum

Dichanthelium dichotomum — forked rosette-panicgrass

Facts

Forked rosette-panicgrass is widespread in New England. It is found in dry to moist soils of woodlands, rocky forests and sandy roadsides, or in wet soils of swamps, wetland margins and other wet sites. There are three subspecies, one of which (Dichanthelium dichotomum ssp. mattamuskeetense) is found only in Massachusetts and Rhode Island, and is rare and protected.

Habitat

Anthropogenic (man-made or disturbed habitats), bogs, cliffs, balds, or ledges, forests, meadows and fields, shores of rivers or lakes, swamps, wetland margins (edges of wetlands), woodlands

Characteristics

• Flowers

  Anther number

  0–3

  Awn on glume

  the glume has no awn

  Bristles below spikelets

  no

  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

  • both glumes are as long or longer than all of the florets
  • neither glume is quite as long as all of the florets

  Glume shape

  the glume is flat or curved in cross-section

  Glume veins

  • 1
  • 3
  • 5
  • 7 or more

  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

  30–120 mm

  Inflorescence type (general)

  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

  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 cross-section

  the lemma is flat or rounded if you cut across the midpoint

  Lemma hairs

  • the lemma has fine hairs between the veins
  • the lemma is hairless between the veins

  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 vein number

  • 3
  • 5
  • 7 or more

  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 no extension of the spikelet axis beyond the tip of the spikelet

  Spikelet length

  1.5–2.5 mm

  Spikelets spiny

  the spikelets do not appear spiny

  Upper glume shape

  the upper glume is widest at or below the middle

• Growth form

  Lifespan

  the plant lives more than two years

  Roots

  the plant has a root mass with a hardened top

• Leaves

  Basal leaves

  the plant has large or prominent tufts of leaves at the base of the flowering stem

  Leaf auricles

  the leaves do not have auricles

  Leaf blade base

  • the leaf blade cuts in abruptly to the narrower base, or has rounded lobes on either side of the base (heart-shaped)
  • the leaf blade is rounded in to a narrower base, or the blade cuts in abruptly to the narrower base
  • the leaf is tapered gradually to the base

  Leaf blade width

  5–14 mm

  Leaf ligule length

  0–1 mm

  Leaf ligule type

  the leaf ligule is in the form of 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

  Orientation of topmost leaf

  • the flag leaf is held outward at more than a 45 degree angle from the stem, or it curves downwards from the horizontal
  • 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
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • bogs
  • cliffs, balds, or ledges
  • edges of wetlands
  • forests
  • man-made or disturbed habitats
  • meadows or fields
  • shores of rivers or lakes
  • swamps
  • woodlands

• Stem, shoot, branch

  Hairs at nodes

  • the stem nodes are hairless or they have very sparse hairs
  • the stem nodes have hairs that stand out at a shallow angle, or they curve downwards

  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