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Elymus villosus — downy wild-rye

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Facts

Downy wild-rye is a rare species of floodplain forests, river banks, rich forests and open soils near the coast. There are two varieties, both of conservation concern. In its floodplain habitats, it may be threatened by changes in hydrology as well as invasive species. It is distinctive for its bristly, arching inforescence and leaves, both of which are softly hairy. Also, the awns are straight, not curved as in other Elymus species of similar habitats.

Habitat

Floodplain (river or stream floodplains), forests, meadows and fields

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
  • Massachusetts
  • Rhode Island
  • Vermont
Leaf blade width
4–12 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
7–12 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 an awn
One or more florets
  • there is more than one floret per spikelet
  • there is one floret per spikelet
Lemma awn length
9–33 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 1 mm
Anther length
1.6–4 mm
Show all characteristics
  • Flowers

    Anther length
    1.6–4 mm
    Anther number
    3
    Awn on glume
    the glume has an awn
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is thin and flexible
    Floret number
    1–3
    Floret types within spikelet
    there are at least two distinct forms of florets within one spikelet
    Glume awn length
    5–25 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
    Glume veins
    3
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis hairs
    • the inflorescence axis is hairy but not rough or sand-papery feeling
    • the inflorescence axis is smooth and has no hairs
    Inflorescence axis orientation
    • the inflorescence axis bends downwards or hangs
    • the inflorescence axis is arched or curved outward
    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
    40–120 mm
    Inflorescence length to width ratio
    2.7–3.4
    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
    15–35 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
    9–33 mm
    Lemma awn number
    the lemma has one awn on it
    Lemma awn orientation
    the awn of the lemma is straight
    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
    • the lemma is hairless between the veins
    Lemma marginal vein hairs
    • the marginal vein of the lemma has fine hairs on it
    • 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
    7–25 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
    • there is one floret per spikelet
    Palea length
    5–7.5 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
    • the spikelet breaks off below the glumes
    Spikelet length
    7–12 mm
    Spikelet number per node
    Up to 3
    Spikelet pedicel
    the spikelets do not have pedicels
    Spikelet pedicel length
    0 mm
    Spikelet position
    NA
    Spikelet shape
    • the spikelets are obovate (egg-shaped but with the widest point above the middle) in profile
    • the spikelets are obtriangular (triangular, with the widest end away from the point of attachment) in profile
    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
    7–25 mm
    Upper glume relative length
    the upper glume is more than one half as long as the lowest lemma
  • 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
    Roots
    there are only slender roots on the plant
  • Leaves

    Leaf auricles
    the leaves have auricles
    Leaf blade cross-section
    the leaf blade is more or less flat in cross-section, or slightly folded or rolled inwards
    Leaf blade hairs
    the leaf blade is hairy
    Leaf blade length
    10–20 cm
    Leaf blade texture
    the leaf blade is smooth, or it may have soft hairs
    Leaf blade width
    4–12 mm
    Leaf ligule length
    Up to 1 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
    New England state
    • Connecticut
    • Massachusetts
    • Rhode Island
    • Vermont
    Specific habitat
    • forests
    • meadows or fields
    • river or stream floodplains
  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    40–130 cm
    Stem node number
    4–8
    Stem orientation
    the stems are upright
    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland status

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

In New England

Distribution

Connecticut
present
Maine
absent
Massachusetts
present
New Hampshire
absent
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
extremely rare (S-rank: S1), endangered (code: E)

var. arkansanus

Vermont
historical (S-rank: SH)

var. villosus

Rhode Island
extremely rare (S-rank: S1), concern (uncertain) (code: C*)
Vermont
extremely rare (S-rank: S1)

Subspecies and varieties

Variety villosus is known from CT, MA, RI, VT. Variety arkansanus is known from CT, MA, VT and is much rarer than variety villosus. Both varieties are of conservation concern.

From Flora Novae Angliae dichotomous key

9.  Elymus villosus Muhl. ex Willd. NC

downy wild-rye. 9a. Elymus canadensis L. var. villosus (Muhl. ex Willd.) Shinners; E. striatus Willd. var. villosus (Muhl. ex Willd.) Gray; 9b. Elymus arkansanus Scrib. & Ball • CT, MA, RI, VT. High-terrace floodplain forests, river banks, rich, rocky forests, open soils near the coast.

1a.  Glumes and lemmas villous to hirsute … 9a. E. villosus var. villosus

1b.  Glumes and lemmas glabrous or scabrous 
 … 9b. E. villosus var. arkansanus (Scribn. & Ball) J.J.N. Campb.

Variety villosus is known from CT, MA, RI, VT. Variety arkansanus is known from CT, MA, VT and is much rarer than variety villosus. Both varieties are of conservation concern.

Native to North America?

Yes

Sometimes confused with

Elymus riparius:
leaf blades glabrous or scabrous on the adaxial surface, internodes of spike mostly 3-5 mm long, and lemmas usually minutely scabrous (vs. E. villosus, with leaf blades softly pubescent on the adaxial surface, internodes of spike mostly 2-3 mm long, and lemmas usually villous).

Synonyms

  • Elymus canadensis L. var. villosus (Muhl. ex Willd.) Shinners
  • Elymus striatus Willd. var. villosus (Muhl. ex Willd.) Gray

Family

Poaceae

Genus

Elymus