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- Dichotomous Key
- Poaceae
- Poaceae Group 5
- Lolium
- Lolium temulentum
Lolium temulentum — darnel rye-grass, poison darnel
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Facts
Poison darnel is a non-native grass that grows in cultivated fields and other areas with disturbed soil. It is found in Connecticut, Massachusetts, Maine and Vermont.
Habitat
Anthropogenic (human-disturbed or -maintained habitats)
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
- Maine
- Massachusetts
- Rhode Island
- Vermont
 
- Leaf blade width
- 1.5–12 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
- 8–28 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
- Up to 23 mm
- Anther length
- 1.5–4 mm
- 
                        Flowers- Anther length
- 1.5–4 mm
 - Anther number
- 3
 - Awn on glume
- the glume has no awn
 - Bristles below spikelets
- no
 - Floret lower bract texture
- the lemma is thin and flexible
 - Floret number
- 2–10
 - Floret types within spikelet
- all the florets within a spikelet are similar
 - Glume awn length
- 0 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 shape
- the glume is flat or curved in cross-section
 - Glume veins
- 
                                
                                    - 3
- 5
- 7 or more
 
 - Glumes per spikelet
- 
                                
                                    - 1
- 2
 
 - Inflorescence arrangement
- the spikelets are uniform
 - 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
- 50–400 mm
 - 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)
 - Lemma awn base
- the awn is attached at the upper half of the lemma
 - Lemma awn coiled
- 
                                
                                    - NA
- the lemma awn is straight or twisted, but not coiled one half turn
 
 - Lemma awn length
- Up to 23 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
 - Lemma base hair length
- 0 mm
 - Lemma base hairs
- the lemma is hairless or feels just a tiny bit rough at the base
 - Lemma cross-section
- the lemma is flat or rounded if you cut across the midpoint
 - Lemma keel hairs
- NA
 - 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
- 5
- 7 or more
 
 - Lemma vein orientation
- the veins on the lemma stay roughly parallel throughout
 - Lower glume length
- 0–28 mm
 - One or more florets
- there is more than one floret per spikelet
 - Palea relative length
- 
                                
                                    - palea is longer than lemma
- 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
- 8–28 mm
 - Spikelet number per node
- Up to 1
 - Spikelet pedicel
- the spikelets do not have pedicels
 - Spikelet pedicel length
- 0 mm
 - Spikelet position
- NA
 - Spikelet width
- 3–8 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
- 5.5–28 mm
 - Upper glume shape
- 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
 - Seed length
- 3.8–7 mm
 
- 
                        Growth form- Horizontal rooting stem
- no
 - Lifespan
- the plant lives only a single year or less
 
- 
                        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 hairless, but it may have tiny prickles that give it a sand-papery feel
 - Leaf blade length
- 1–12 cm
 - Leaf blade width
- 1.5–12 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 hairs
- there are no hairs on the surface of the leaf sheath
 
- 
                        Place- Habitat
- terrestrial
 - New England state
- 
                                
                                    - Connecticut
- Maine
- Massachusetts
- Rhode Island
- Vermont
 
 - Specific habitat
- human-disturbed or -maintained habitats
 
- 
                        Stem, shoot, branch- Hairs at nodes
- the stem nodes are hairless or they have very sparse hairs
 - Plant height
- Up to 120 cm
 - Stem hairs
- 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
 
Wetland status
Not classified
In New England
Distribution
- Connecticut
- present
- Maine
- present
- 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.
ssp. temulentum
- Massachusetts
- not applicable (S-rank: SNA)
Subspecies and varieties
Our subspecies is Lolium temulentum L. ssp. temulentum.
From Flora Novae Angliae dichotomous key
3. Lolium temulentum L. ssp. temulentum E
poison darnel. Lolium arvense With.; L. temulentum L. var. arvense (With.) Lilja • CT, MA, ME, RI, VT. Areas of cultivation, disturbed soil.
Native to North America?
No
Sometimes confused with
- Lolium multiflorum:
- glume 3.5–15 mm long, the body 0.25–0.75 times as tall as the column of florets, and plants annual or perennial, with mostly 5- to 22-flowered spikelets (vs. L. temulentum, with the glume mostly 7–28 mm long, the body 0.75–1.5 times as tall as the column of florets, plants annual, with 2- to 10-flowered).
- Lolium perenne:
- glume 3.5–15 mm long, the body 0.25–0.75 times as tall as the column of florets, and plants annual or perennial, with mostly 5- to 22-flowered spikelets (vs. L. temulentum, with the glume mostly 7–28 mm long, the body 0.75–1.5 times as tall as the column of florets, plants annual, with 2- to 10-flowered).
Synonyms
- Lolium arvense With.
- Lolium temulentum L. var. arvense (With.) Lilja
 
                        ![Plant form: Lolium temulentum. ~ By William and Linda Steere and the C.V. Starr Virtual Herbarium. ~ Copyright © 2025 William and Linda Steere and the C.V. Starr Virtual Herbarium. ~ Barbara Thiers, Director; bthiers[at]nybg.org ~ C.V. Starr Herbarium - NY Botanical Gardens](https://newfs.s3.amazonaws.com/taxon-images-239x239/Poaceae/lolium-temulentum-ha-cvstarr1.jpg) 
                         
                         
                         
                         
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