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Trisetum spicatum — narrow false oat

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Facts

Narrow false oat is globally one of the most widespread flowering plants, present in arctic and alpine regions of all continents except Africa. It is widespread across northern and western North America, as well as in most New England states. In our region it is found on rivershore outcrops and ledges, and sometimes at higher altitudes, preferring calcareous bedrock.

Habitat

Alpine or subalpine zones, forests, ridges or ledges, shores of rivers or lakes, woodlands

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
Leaf blade width
1–4 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
5–7.5 mm
Glume relative length
  • neither glume is quite as long as all of the florets
  • 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
3–8 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
0.5–4 mm
Anther length
0.6–1.4 mm
Show all characteristics
  • Flowers

    Anther length
    0.6–1.4 mm
    Anther number
    3
    Awn on glume
    the glume has no awn
    Glume relative length
    • neither glume is quite as long as all of the florets
    • one or both glumes are as long or longer than all of the florets
    Glume veins
    3
    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 crowding
    the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    Inflorescence length
    50–500 mm
    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
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn base
    the awn is attached at the upper half of the lemma
    Lemma awn length
    3–8 mm
    Lemma awn number
    the lemma has one awn on it
    Lemma base hairs
    the lemma has hairs at the base
    Lemma cross-section
    the lemma is V-shaped if you cut across the midpoint
    Lemma surface
    the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)
    Lemma vein number
    • 3
    • 5
    • 7 or more
    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 length
    5–7.5 mm
    Spikelets spiny
    the spikelets do not appear spiny
    Upper glume shape
    the upper glume is widest at or below the middle
  • Leaves

    Leaf auricles
    the leaves do not have auricles
    Leaf blade width
    1–4 mm
    Leaf ligule length
    0.5–4 mm
    Leaf ligule type
    the leaf ligule is in the form of a membrane
    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 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
    Orientation of topmost leaf
    the flag leaf is held upright, or at less than a 45 degree angle out from the stem
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • forests
    • ridges or ledges
    • shores of rivers or lakes
    • woodlands
  • Stem, shoot, branch

    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland status

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

In New England

Distribution

Connecticut
present
Maine
present
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.

Connecticut
extremely rare (S-rank: S1), endangered (code: E)
Maine
fairly widespread (S-rank: S4)
Massachusetts
extremely rare (S-rank: S1), endangered (code: E)
New Hampshire
unrankable (S-rank: SU), Ind (code: Ind)

var. molle

Connecticut
extremely rare (S-rank: S1)

var. pilosiglume

Vermont
extremely rare (uncertain) (S-rank: S1?)

var. spicatum

Vermont
uncommon (S-rank: S3)

From Flora Novae Angliae dichotomous key

2.  Trisetum spicatum (L.) Richter N

narrow false oat. Aira spicata L.; Trisetum spicatum (L.) Richter var. molle (Kunth) Beal; 
 T. spicatum (L.) Richter var. psilosiglume Fern.; T. triflorum (Bigelow) A. & D. Löve • CT, MA, ME, NH, VT; also reported from RI by Kartesz (1999), but specimens are unknown. River shore outcrops, ledges, often in regions of high-pH bedrock and ascending to subalpine situations.

Native to North America?

Yes

Sometimes confused with

Corynephorus canescens:
leaf blades up to 1 mm wide and lemma awn comprised of two distinct and dissimilar parts with a ring of cilia near the middle at the articulation point (vs. T. spicatum, with leaf blades 1-5 mm wide and lemma awns comprised not comprised of two distinct parts and without a ring of cilia near the middle of the awn).

Synonyms

  • Aira spicata L.
  • Trisetum spicatum (L.) Richter var. molle (Kunth) Beal
  • Trisetum spicatum (L.) Richter var. psilosiglume Fern.
  • Trisetum triflorum (Bigelow) A. & D. Löve

Family

Poaceae

Genus

Trisetum