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- Dichotomous Key
- Poaceae
- Poaceae Group 4
- Schedonorus
- Schedonorus giganteus
Schedonorus giganteus — giant rye grass
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Facts
N/A
Habitat
Anthropogenic (man-made or disturbed 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
- Leaf blade width
- 4–18 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 8–20 mm
- Glume relative length
- neither glume is quite as long as 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
- 10–18 mm
- Leaf sheath hair type
- there are no hairs on the surface of the leaf sheath
- Leaf ligule length
- 0.5–2.5 mm
- Anther length
- 2.5–3 mm
-
Flowers
- Anther length
- 2.5–3 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
- 3–10
- Floret types within spikelet
- all the florets within a spikelet are similar
- Glume awn length
- 0 mm
- Glume keel
- NA
- Glume relative length
- neither glume is quite as long as all of the florets
- Glume shape
- the glume is flat or curved in cross-section
- Glume veins
-
- 1
- 3
- 5
- Glumes per spikelet
- 2
- Inflorescence arrangement
- the spikelets are uniform
- Inflorescence axis orientation
-
- the inflorescence axis bends downwards or hangs
- the inflorescence axis is arched or curved outward
- the inflorescence axis is straight
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Inflorescence branches coming off the lowest stem node
- 2
- Inflorescence crowding
- the panicle is somewhat to very spread out, with clearly-evident branches
- Inflorescence length
- 80–500 mm
- Inflorescence type (general)
- 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 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
- 10–18 mm
- Lemma awn number
- 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
- 5
- Lemma vein orientation
- the veins on the lemma come together near the tip
- Lower glume length
- 4–7 mm
- Lower glume relative length
-
- the lower glume is nearly as long, or as long as, the upper glume
- the lower glume is one third to three quarters as long as the upper glume
- 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
- 8–20 mm
- Spikelet number per node
- Up to 0
- Spikelet pedicel
- the spikelets have pedicels
- Spikelet shape
- the spikelets are lanceolate (lance-shaped, widest below the middle and tapering narrowly to the ends) in profile
- Spikelet width
- 1.5–2.5 mm
- 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
- 5–8 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
- 3–4.6 mm
-
Growth form
- Horizontal rooting stem
- no
- Lifespan
- the plant lives more than two years
-
Leaves
- Leaf auricles
- the leaves have auricles
- Leaf basal lobe hairy
- the lobes at the base of the leaf blades are hairless
- Leaf blade cross-section
- the leaf blade is more or less flat in cross-section, or slightly folded or rolled inwards
- Leaf blade length
- 10–40 cm
- Leaf blade width
- 4–18 mm
- Leaf ligule length
- 0.5–2.5 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 no hairs on the surface of the leaf sheath
- Leaf sheath hairs
- there are no hairs on the surface of the leaf sheath
-
Place
- Habitat
- terrestrial
- New England state
- Connecticut
- Specific habitat
- man-made or disturbed habitats
-
Stem, shoot, branch
- Plant height
- Up to 150 cm
- Stem node number
- 2–5
- 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
- absent
- New Hampshire
- absent
- Rhode Island
- absent
- Vermont
- absent
Conservation status
None
From Flora Novae Angliae dichotomous key
2. Schedonorus giganteus (L.) Holub E
giant rye grass. Bromus giganteus L.; Festuca gigantea (L.) Vill.; Lolium giganteum (L.) Darbyshire • CT. Waste areas, disturbed soil.
Native to North America?
No
Sometimes confused with
- Schedonorus pratensis:
- lemma awns absent or up to 4 mm long and leaf blades mostly 2–7 mm wide (vs. S. giganteus, with lemma awns 10–18 mm long and leaf blades mostly 6–18 mm wide).
- Schedonorus arundinaceus:
- lemma awns absent or up to 4 mm long and leaf blades mostly 4–12 mm wide (vs. S. giganteus, with lemma awns 10–18 mm long and leaf blades mostly 6–18 mm wide).
Synonyms
- Bromus giganteus L.
- Festuca gigantea (L.) Vill.
- Lolium giganteum (L.) Darbyshire