Elymus trachycaulus (Link) Gould ex Shinners

wheatgrass

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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

Slender wild-rye is a widespread native of gravelly and ledgy river shores, cliffs and talus slopes, as well as open areas near the coast, and a range of wetlands. There are two subspecies recognized in New England. This versatile plant grows from Greenland to Mexico, and is introduced to Asia. Its forms are quite plastic -- forest-dwelling plants flower later and are more slender and tall than grassland-inhabiting forms. Its upright spikelets are tightly arrayed in a zig-zig up a long flowering stem.

Habitat

Bogs, cliffs, balds, or ledges, fens, forests, meadows and fields, ridges or ledges, shores of rivers or lakes, talus and rocky slopes, woodlands

Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
2–8 mm
Inflorescence branches
there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
Spikelet length
9–20 mm
Glume relative length
  • both glumes are as long or longer than all of the florets
  • neither glume is quite as long as all of the florets
Awn on glume
  • the glume has an awn
  • the glume has no awn
One or more florets
there is more than one floret per spikelet
Lemma awn length
0–24 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
0.2–0.8 mm
Anther length
0.8–3 mm
Show All Characteristics
  • Flowers
    Anther length
    0.8–3 mm
    Anther number
    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 thin and flexible
    Floret number
    3–8
    Floret types within spikelet
    there are at least two distinct forms of florets within one spikelet
    Glume awn length
    0–11 mm
    Glume keel
    • the glume keels are rough or hairy
    • the glume keels are smooth and hairless
    Glume relative length
    • both glumes are as long or longer than all of the florets
    • neither glume is quite as long as all of the florets
    Glume veins
    • 3
    • 5
    • 7 or more
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis hairs
    • the inflorescence axis is rough and feels like sand-paper
    • the inflorescence axis is smooth and has no hairs
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branch length
    0 cm
    Inflorescence branch roughness
    NA
    Inflorescence branches
    there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
    Inflorescence branches coming off the lowest stem node
    0
    Inflorescence crowding
    NA
    Inflorescence length
    40–250 mm
    Inflorescence length to width ratio
    20–31.3
    Inflorescence type (general)
    the inflorescence is a spike, or is spike-like, lacking obvious branches
    Inflorescence type (specific)
    the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)
    Inflorescence width
    2–8 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
    0–24 mm
    Lemma awn number
    • the lemma has no awn
    • the lemma has 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 hairs
    the lemma is hairless between the veins
    Lemma keel hairs
    • NA
    • the keel of the lemma is hairless
    • the keel of the lemma is rough, or has fine hairs
    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 tip shape
    the lemma tip tapers to a narrow point (it may or may not also have an awn or teeth at the tip)
    Lemma vein number
    • 5
    • 7 or more
    Lemma vein orientation
    the veins on the lemma stay roughly parallel throughout
    Lower glume length
    5–17 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 length
    7–9 mm
    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
    9–20 mm
    Spikelet number per node
    At least 1
    Spikelet pedicel
    the spikelets do not have pedicels
    Spikelet pedicel length
    0 mm
    Spikelet position
    NA
    Spikelet shape
    • the spikelets are elliptic (widest in the middle, tapering to the ends) in profile
    • the spikelets are oblong (rectangular, but with rounded ends) in profile
    Spikelet width
    3–6 mm
    Spikelets per panicle branch
    0
    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
    5–17 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 above the middle
    • 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
    Horizontal rooting stem
    no
    Lifespan
    the plant lives more than two years
    Rhizomes
    • no
    • yes
    Roots
    • the plant has rhizomes (horizontal underground stem with roots growing from it)
    • 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
    • the plant has large or prominent tufts of leaves at the base of the flowering stem
    Leaf auricles
    • the leaves do not have auricles
    • the leaves have auricles
    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 hairs
    • the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
    • the leaf blade is hairy
    Leaf blade length
    Up to 20 cm
    Leaf blade texture
    the leaf blade is smooth, or it may have soft hairs
    Leaf blade width
    2–8 mm
    Leaf ligule length
    0.2–0.8 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 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 outward at more than a 45 degree angle from the stem, or it curves downwards from the horizontal
    • the flag leaf is held upright, or at less than a 45 degree angle out from the stem
  • Place
    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • bogs
    • cliffs, balds, or ledges
    • fens
    • forests
    • meadows or fields
    • ridges or ledges
    • shores of rivers or lakes
    • talus or rocky slopes
    • woodlands
  • Stem, shoot, branch
    Hairs at nodes
    • the stem nodes are hairless or they have very sparse hairs
    • the stem nodes have hairs that stand out at a shallow angle, or they curve downwards
    Plant height
    30–150 cm
    Stem hairs
    • the stem has hairs on it
    • 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
    • the stems grow singly or a few together (they may form diffuse colonies)

Wetland Status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England Distribution and Conservation Status

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
unrankable (S-rank: SU)
Massachusetts
unranked (S-rank: SNR)
Vermont
uncommon (S-rank: S3)

ssp. glaucus

New Hampshire
unrankable (S-rank: SU), Ind (code: Ind)

ssp. subsecundus

Connecticut
fairly widespread (S-rank: S4)
Massachusetts
unranked (S-rank: SNR)

ssp. trachycaulus

Connecticut
unrankable (S-rank: SU)
Massachusetts
unranked (S-rank: SNR), #NAME? (code: #NAME?)
New Hampshire
unrankable (S-rank: SU), Ind (code: Ind)

Native to North America?

Yes

Sometimes Confused With

Thinopyrum pycnanthum:
anthers 5-7 mm long, and glumes acute at the apex, unawned or with a tiny mucro to 0.5 mm long (vs. E. trachycaulus, with anthers 1-2 mm long, and glumes long-acute at the apex, usually with an awn mostly 0.5-4 mm long).
Elymus repens:
anthers 3-7 mm long and plants not cespitose, with rhizomes (vs. E. trachycaulus, with anthers 1-2 mm long and plants cespitose, without rhizomes).

Family

Poaceae

Genus

Elymus

Notes on Subspecies and Varieties in New England

Subspecies glaucus is known from CT, MA, ME, NH, VT. Subspecies trachycaulus is known from CT, MA, ME, NH, RI, VT. Elymus subsecundus (synonym: E. trachycaulus var. unilateralis (Cassidy) Beetle) was reported from New England based on specimens with evident lemmas awns. These plants are, in fact, intermediate between E. trachycaulus and E. subsecundus and have been referred to by the epithet “ glaucus” by Fernald (1950b). Jozwik (1966) suggested that such plants with intermediate awn length and sometimes divergent awns are often hybrids between E. trachycaulus and E. subsecundus. If this hypothesis is confirmed, ssp. glaucus should be recognized at the specific level to ensure its name does not imply an incorrect evolutionary relationship.

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Information from Dichotomous Key of Flora Novae Angliae

8.  Elymus trachycaulus (Link) Gould ex Shinners N

slender wild-rye.  1a. Agropyron caninum (L.) Beauv. var. pubescens Scribn. & J.G. Sm.; 
 A. trachycaulum (Link) Malte var. glaucum (Pease & Moore) Malte;  1b. Agropyron trachycaulum (Link) Malte ex H.F. Lewis; A. trachycaulum (Link) Malte ex H.F. Lewis var. majus (Vasey) Fern.; A. trachycaulum (Link) Malte ex H.F. Lewis var. novae-angliae (Scribn.) Fern.; Triticum trachycaulum L. • CT, MA, ME, NH, RI, VT. Gravelly and ledgy river shores, cliffs and talus fields, open areas near the coast, peatlands, pond shores, roadsides, fields, swamp edges.

1a.  Lemma awns 5–17 (–24) mm long, straight or curving outward from the axis of the spike; glume awns 0–10 mm long … 8a. E. trachycaulus ssp. glaucus (Pease & Moore) Cody

1b.  Lemma awns wanting or represented by a short awn-tip (rarely as long as 5 mm 
and straight); glume awns absent or represented by a short awn-tip 
 … 8b. E. trachycaulus ssp. trachycaulus

Subspecies glaucus is known from CT, MA, ME, NH, VT. Subspecies trachycaulus is known from CT, MA, ME, NH, RI, VT. Elymus subsecundus (synonym: E. trachycaulus var. unilateralis (Cassidy) Beetle) was reported from New England based on specimens with evident lemmas awns. These plants are, in fact, intermediate between E. trachycaulus and E. subsecundus and have been referred to by the epithet “ glaucus” by Fernald (1950b). Jozwik (1966) suggested that such plants with intermediate awn length and sometimes divergent awns are often hybrids between E. trachycaulus and E. subsecundus. If this hypothesis is confirmed, ssp. glaucus should be recognized at the specific level to ensure its name does not imply an incorrect evolutionary relationship.