Avena fatua L.

wild oat

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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

Wild oat is considered a noxious weed in many parts of the world, having spread from Europe and Central and Southwest Asia to temperate areas worldwide. It was introduced to North America by early European settlers, and is now a common weed of seed crops. It is also frequently found as a contaminant in seed, feed and silage. The twisted lemma awn coils and uncoils in response to changes in humidity and can help corkscrew the seed into the ground.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
Leaf blade width
3–15 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
18–32 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
23–42 mm
Leaf ligule length
4–6 mm
Show All Characteristics
  • Flowers
    Anther number
    3
    Awn on glume
    the glume has no awn
    Floret lower bract texture
    • the lemma is hard and firm
    • the lemma is thin and flexible
    Floret number
    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 veins
    7 or more
    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 length
    70–400 mm
    Inflorescence length to width ratio
    1.4–2
    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
    50–200 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
    23–42 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
    3.5–5.5 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 has fine hairs between the veins
    Lemma keel hairs
    the keel of the lemma is rough, or has fine hairs
    Lemma marginal vein hairs
    the marginal vein of the lemma has fine hairs on it
    Lemma surface
    the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)
    Lemma tip
    the lemma tip is split into two or more points
    Lemma vein number
    • 5
    • 7 or more
    Lower glume length
    18–32 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
    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
    18–32 mm
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet position
    the spikelets emerge from both the upper and lower halves of the inflorescence branches
    Spikelets spiny
    the spikelets do not appear spiny
    Upper glume length
    18–32 mm
    Upper glume shape
    the upper glume is widest at or below the middle
  • Fruits or seeds
    Groove on seed
    the caryopsis has a groove running most of its length
  • Growth form
    Lifespan
    the plant lives only a single year or less
  • Leaves
    Leaf auricles
    the leaves do not have auricles
    Leaf basal lobe hairy
    NA
    Leaf blade hairs
    the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
    Leaf blade length
    10–45 cm
    Leaf blade texture
    the leaf blade is rough and sandpapery
    Leaf blade width
    3–15 mm
    Leaf ligule length
    4–6 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 hairs
    • there are hairs on the surface of the leaf sheath
    • there are no hairs on the surface of the leaf sheath
  • Place
    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Stem, shoot, branch
    Plant height
    8–160 cm
    Stem orientation
    • the stems are upright
    • the stems trail at the base, but turn upwards at the tips
    Stem spacing
    • the stems grow close together in compact clusters or tufts
    • the stems grow singly or a few together (they may form diffuse colonies)

Wetland Status

Not classified

New England Distribution and Conservation Status

Distribution

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

Conservation Status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
not applicable (S-rank: SNA)

Native to North America?

No

Sometimes Confused With

Avena sativa:
lemmas glabrous and spikelets usually with 2 florets (vs. A. fatua, with lemmas pubescent with appressed, brown hairs and spikelets usually with 3 florets).
Avena strigosa:
lemmas scabrous near the apex but otherwise without hairs and spikelets usually with 2 florets (vs. A. fatua, with lemmas pubescent with appressed, brown hairs and spikelets usually with 3 florets).

Synonyms

  • Avena fatua L. var. glabrata Peterm.

Family

Poaceae

Genus

Avena

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Information from Dichotomous Key of Flora Novae Angliae

1.  Avena fatua L. E

wild oat. Avena fatua L. var. glabrata Peterm. • CT, MA, ME, NH, VT. Fields, roadsides, disturbed soil.