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Native Plant Trust: Go Botany Discover thousands of New England plants

Anthoxanthum odoratum — large sweet grass, sweet vernalgrass

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Facts

Native Americans used large sweet grass to make baskets. It has often been included in hay and pasture mixtures for its fragrance, but since it was discovered that cattle find it unpalatable, this practice is waning.

Habitat

Anthropogenic (man-made or disturbed habitats), cliffs, balds, or ledges, forest edges, grassland, meadows and fields, ridges or ledges, woodlands

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
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
2–10 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
7–9 mm
Glume relative length
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
2–9 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
Leaf ligule length
2–7 mm
Anther length
2.9–5.5 mm
Show all characteristics
  • Flowers

    Anther length
    2.9–5.5 mm
    Anther number
    2–3
    Awn on glume
    the glume has no awn
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is hard and firm
    Floret number
    3
    Floret types within spikelet
    there are at least two distinct forms of florets within one spikelet
    Glume awn length
    0 mm
    Glume keel
    • the glume keels are rough or hairy
    • the glume keels are smooth and hairless
    Glume relative length
    one or both glumes are as long or longer than all of the florets
    Glume shape
    the glume is V-shaped in cross-section
    Glume veins
    • 1
    • 3
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis hairs
    the inflorescence axis is smooth and has no hairs
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branch length
    10–25 cm
    Inflorescence branch roughness
    the inflorescence branches are smooth or only slightly rough
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence crowding
    the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    Inflorescence length
    30–140 mm
    Inflorescence length to width ratio
    2–7
    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
    Inflorescence width
    15–20 mm
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn base
    • the awn is attached at the lower half of the lemma (it emerges from near the base of the lemma)
    • the awn is attached at the upper half of the lemma
    Lemma awn coiled
    the lemma awn is straight or twisted, but not coiled one half turn
    Lemma awn length
    2–9 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 cross-section
    the lemma is flat or rounded if you cut across the midpoint
    Lemma hairs
    the lemma has fine hairs between the veins
    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)
    Lower glume length
    3–4 mm
    Lower glume relative length
    • the lower glume is one third or less 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 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
    7–9 mm
    Spikelet number per node
    0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet pedicel length
    0.5–1 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
    8–10 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 at or below the middle
  • Fruits or seeds

    Seed length
    1.6–1.8 mm
  • 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

    Basal leaves
    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 basal lobe hairy
    the lobes at the base of the leaf blades have tiny fine hairs on them
    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
    • the leaf blade is hairy
    Leaf blade length
    1–31 cm
    Leaf blade texture
    the leaf blade is smooth, or it may have soft hairs
    Leaf blade width
    2–10 mm
    Leaf ligule length
    2–7 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
    Leaf sheath hairs
    there are hairs on the surface of the leaf sheath
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • cliffs, balds, or ledges
    • edges of forests
    • grasslands
    • man-made or disturbed habitats
    • meadows or fields
    • ridges or ledges
    • woodlands
  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    10–100 cm
    Stem hairs
    the stem is nearly to completely hairless
    Stem orientation
    the stems are upright
    Stem spacing
    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)

In New England

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.

Massachusetts
widespread (S-rank: S5)

From Flora Novae Angliae dichotomous key

4.  Anthoxanthum odoratum L. E

large sweet grass. CT, MA, ME, NH, RI, VT; throughout. Fields, roadsides, lawns, forest edges 
and openings.

Native to North America?

No

Sometimes confused with

Anthoxanthum ovatum:
leaf blades mostly narrower than 2 mm, spikelets 5-7 mm long, and plants annual with geniculate stems (vs. A. odoratum, with leaf blades 2-6 mm wide, spikelets 7-9 mm long, and plants perennial with erect stems).

Family

Poaceae

Genus

Anthoxanthum