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- Poaceae Group 5
- Elymus
- Elymus villosus
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
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
- 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
-
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