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- Avena strigosa
Avena strigosa — lopsided oat
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Facts
The cultivation of lopsided oat in Europe, where it was formerly grown in marginal environments in place of oat (Avena sativa) has all but ended, although it is widely grown in Brazil as a cover and forage crop. In North America, this species has been collected in California and Massachusetts, but is not a common weed.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
- Massachusetts
- Leaf blade width
- Up to 10 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 14–26 mm
- Glume relative length
- one or 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
- 3–35 mm
- Leaf ligule length
- 2–5 mm
- Anther length
- 2.5–4 mm
-
Flowers
- Anther length
- 2.5–4 mm
- 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
- 2
- Floret types within spikelet
- all the florets within a spikelet are similar
- Glume relative length
- one or 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
- 80–300 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
- 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
- 3–35 mm
- Lemma awn number
- the lemma has one awn on it
- Lemma cross-section
- the lemma is flat or rounded if you cut across the midpoint
- Lemma keel hairs
- the keel of the lemma is rough, or has fine hairs
- 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
- 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 length
- 14–26 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 only a single year or less
-
Leaves
- Leaf auricles
- the leaves do not have auricles
- Leaf blade width
- Up to 10 mm
- Leaf ligule length
- 2–5 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)
-
Place
- Habitat
- terrestrial
- New England state
- Massachusetts
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
Wetland status
Not classified
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- absent
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
3. Avena strigosa Schreb. E
lopsided oat. MA. Fields, roadsides, disturbed soil.
Native to North America?
No
Sometimes confused with
- Avena sativa:
- lemmas glabrous and inflorescence not secund (vs. A. strigosa, with lemmas scabrous near the apex and inflorescence secund).
- Avena fatua:
- lemmas pubescent with appressed, brown hairs and spikelets usually with 3 florets (vs. A. strigosa, with lemmas scabrous near the apex but otherwise without hairs and spikelets usually with 2 florets).