Deschampsia danthonioides (Trin.) Munro

annual hair grass

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Annual hair grass is a species of western North America, and a rare visitor to New England, having been collected only from the dump sites of nineteenth-century wool-carding factories in Maine.

Habitat

Anthropogenic (man-made or disturbed habitats)

Characteristics

Habitat
terrestrial
New England state
Maine
Leaf blade width
0.3–1.5 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
4–9 mm
Glume relative length
both glumes are as long or longer than all of the florets
Awn on glume
the glume has no awn
One or more florets
there is more than one floret per spikelet
Lemma awn length
4–9 mm
Leaf sheath hair type
there are no hairs on the surface of the leaf sheath
Leaf ligule length
0.5–4.7 mm
Anther length
0.3–0.5 mm
Show All Characteristics
  • Flowers
    Anther length
    0.3–0.5 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
    2–3
    Floret types within spikelet
    all the florets within a spikelet are similar
    Glume awn length
    0 mm
    Glume relative length
    both glumes are as long or longer than 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 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
    Inflorescence crowding
    • the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    • the panicle is somewhat to very spread out, with clearly-evident branches
    Inflorescence length
    50–250 mm
    Inflorescence length to width ratio
    2.5–3.2
    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
    Inflorescence width
    20–80 mm
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn base
    • the awn is attached at the lower half of the lemma (it emerges from near the base of the lemma)
    • the awn is attached at the upper half of the lemma
    Lemma awn coiled
    the lemma awn is straight or twisted, but not coiled one half turn
    Lemma awn length
    4–9 mm
    Lemma awn number
    the lemma has one awn on it
    Lemma awn orientation
    the awn of the lemma on dried or older plants is curved or bent outwards
    Lemma base hair length
    0.4–1.6 mm
    Lemma base hairs
    the lemma has hairs 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 marginal vein hairs
    the marginal vein of the lemma is hairless
    Lemma surface
    the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)
    Lemma tip
    • the lemma tip has a ragged edge
    • the lemma tip is split into two or more points
    Lemma tip shape
    • the lemma tip is rounded off or truncate (ends abruptly in a more or less straight line as though cut off); it may or may not also have an awn or teeth at the tip
    • the lemma tip tapers to a broad point (it may or may not also have an awn or teeth at the tip)
    Lemma vein number
    5
    Lower glume length
    4–9 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
    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 an extension of the spikelet axis beyond the tip of the spikelet
    Spikelet disintegration
    the spikelet breaks off above the glumes, so that after the florets fall off, the glumes remain
    Spikelet length
    4–9 mm
    Spikelet number per node
    Up to 0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet position
    the spikelets emerge mainly from the upper halves of the inflorescence branches
    Spikelet shape
    the spikelets are obtriangular (triangular, with the widest end away from the point of attachment) 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
    3.5–8.5 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 at or below the middle
  • 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 large or prominent tufts of leaves at the base of the flowering stem
    Leaf auricles
    the leaves do not have auricles
    Leaf basal lobe hairy
    NA
    Leaf blade cross-section
    • the leaf blade is clearly folded or rolled inwards
    • the leaf blade is more or less flat in cross-section, or slightly folded or rolled inwards
    Leaf blade width
    0.3–1.5 mm
    Leaf ligule length
    0.5–4.7 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 color and persistence
    the leaf sheathes are off-white to light-brown and mostly persist in older leaves
    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
  • Place
    Habitat
    terrestrial
    New England state
    Maine
    Specific habitat
    man-made or disturbed habitats
  • Stem, shoot, branch
    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    10–70 cm
    Roots at lower stem nodes
    no
    Stem hairs
    the stem is nearly to completely hairless
    Stem orientation
    the stems are upright
    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland Status

Not classified

New England Distribution and Conservation Status

Distribution

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

Conservation Status

None

Native to North America?

Yes and no (some introduced)

Sometimes Confused With

Deschampsia elongata:
panicles congested, with appressed branches, lemma awns straight or slightly bent, and plants perennial (vs. D. danthonioides, with panicles contracted to open, with erect to ascending branches, lemma awns strongly bent, and plants annual).

Synonyms

  • Aira danthonioides Trin.

Family

Poaceae

Genus

Deschampsia

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Information from Dichotomous Key of Flora Novae Angliae

3.  Deschampsia danthonioides (Trin.) Munro E

annual hair grass. Aira danthonioides Trin. • ME. Wool waste, edges of lawns.