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- Dichotomous Key
- Poaceae
- Poaceae Group 7
- Aristida
- Aristida longespica
Aristida longespica — red threeawn
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Facts
Red threeawn is a small and delicate grass of sandy and disturbed soils. Two varieties are found in New England. The more widespread is the native variety (Aristida longespica var. geniculata), occurring throughout New England, except in Maine. The less widespread variety (A. longespica var. longespica), is found in Connecticut and Massachusetts, and is considered introduced, although it is native to other parts of North America.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields, shores of rivers or lakes, woodlands
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
-
- Connecticut
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Leaf blade width
- 1–2 mm
- 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
- Spikelet length
- 3–4 mm
- Glume relative length
- one or both glumes are as long or longer than all of the florets
- Awn on glume
-
- the glume has an awn
- the glume has no awn
- One or more florets
- there is one floret per spikelet
- Lemma awn length
- 1–27 mm
- Leaf sheath hair type
-
- there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
- there are no hairs on the surface of the leaf sheath
- Leaf ligule length
- Up to 0.5 mm
- Anther length
- 0.2–4 mm
-
Flowers
- Anther length
- 0.2–4 mm
- Anther number
- 1–3
- Awn on glume
-
- the glume has an awn
- the glume has no awn
- Bristles below spikelets
- no
- Floret lower bract texture
- the lemma is hard and firm
- Floret number
- 1
- Floret types within spikelet
- all the florets within a spikelet are similar
- Glume awn length
- Up to 1 mm
- Glume relative length
- one or both glumes are as long or longer than all of the florets
- Glume veins
- 1
- Glumes per spikelet
- 2
- Inflorescence arrangement
- the spikelets are uniform
- Inflorescence axis orientation
- the inflorescence axis is straight
- Inflorescence branch length
- 1–4 cm
- 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
- the panicle is somewhat to very spread out, with clearly-evident branches
- Inflorescence length
- 60–220 mm
- Inflorescence length to width ratio
- 3.7–6
- 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
- Inflorescence width
- 10–60 mm
- Inforescence position
- the spikelets are mainly carried at the end of the stem
- Lemma awn base
- the awn is attached right at the tip of the lemma
- Lemma awn coiled
- the lemma awn is straight or twisted, but not coiled one half turn
- Lemma awn length
- 1–27 mm
- Lemma awn number
- the lemma has more than one awn on it
- Lemma awn orientation
-
- the awn of the lemma is straight
- the awn of the lemma on dried or older plants is curved or bent outwards
- Lemma base hairs
- the lemma has hairs at the base
- Lemma base length
- Up to 1 mm
- 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 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 is a simple point, with or without an awn (long narrow extension ending in a point)
- Lemma vein number
- 3
- Lower glume length
- 2–11 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 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 no 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
- 3–4 mm
- Spikelet number per node
- 0
- Spikelets per panicle branch
- 2–5
- 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
- 2–11 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
-
Fruits or seeds
- Seed length
- 3–4 mm
-
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 few or no leaves coming from 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 more or less flat in cross-section, or slightly folded or rolled inwards
- Leaf blade length
- 5–14 cm
- Leaf blade width
- 1–2 mm
- Leaf ligule length
- Up to 0.5 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 color and persistence
- the leaf sheathes are off-white to light-brown and mostly persist in older leaves
- Leaf sheath hair type
-
- there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
- there are no hairs on the surface of the leaf sheath
- 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
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
- shores of rivers or lakes
- woodlands
-
Stem, shoot, branch
- Plant height
- 15–65 cm
- Stem spacing
- the stems grow close together in compact clusters or tufts
Wetland status
Occurs only in non-wetlands. (Wetland indicator code: UPL)
In New England
Distribution
- Connecticut
- present
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
var. geniculata
- Connecticut
- uncommon (S-rank: S3), special concern (code: SC)
- Massachusetts
- not applicable (S-rank: SNA)
- New Hampshire
- rare (S-rank: S2), threatened (code: T)
- Rhode Island
- rare (S-rank: S2), concern (code: C)
- Vermont
- extremely rare (S-rank: S1)
var. longespica
- Connecticut
- widespread (S-rank: S5)
- Massachusetts
- not applicable (S-rank: SNA)
From Flora Novae Angliae dichotomous key
3. Aristida longespica Poir. n
red threeawn. 3a. Aristida geniculata Raf.; Aristida intermedia Scribn. & Ball; 3b. Aristida gracilis Ell. • CT, MA, NH, RI, VT. Sandy fields, roadsides, woodland openings, disturbed sandy soils, sandy pond shores.
1a. Central awn (8–) 12–27 mm long; lateral awns (1–) 6–18 mm long; glumes 4–11 mm long; flowers with 1 or 3 anthers … 3a. A. longespica var. geniculata (Raf.) Fern.
1b. Central awn 1–10 (–14) mm long; lateral awns 0–5 (–8) mm long; glumes 2–8 mm long; flowers with 1 anther … 3b. A. longespica var. longespica
Variety geniculata is native and known from CT, MA, NH, RI, VT. Variety longespica is non-native and known from CT, MA.
Native to North America?
Yes
Sometimes confused with
- Aristida basiramea:
- central awn coiled at base 2 to 3 full turns and flowers with 3 anthers ca. 3 mm long (vs. A. longespica, with central awn not coiled at base and flowers either with 1 anther that is 0.2-0.3 mm long or 3 anthers that are 3-4 mm long).
Synonyms
- Aristida gracilis Ell.