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

Leersia oryzoides — rice cut grass

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Facts

Rice cut grass has rough leaf sheathes and blade edges that are sharp enough to cut bare skin. It is found on shorelines, in swamps and ditches, and other low, wet areas throughout New England.

Habitat

Lacustrine (in lakes or ponds), meadows and fields, shores of rivers or lakes, swamps, wetland margins (edges of wetlands)

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
  • aquatic
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
5–15 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
4–6.5 mm
Glume relative length
NA
Awn on glume
NA
One or more florets
there is one floret per spikelet
Lemma awn length
0 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
0.5–1 mm
Anther length
1.5–3 mm
Show all characteristics
  • Flowers

    Anther length
    1.5–3 mm
    Anther number
    3
    Awn on glume
    NA
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is thin and flexible
    Floret number
    1
    Floret types within spikelet
    all the florets within a spikelet are similar
    Glume awn length
    0 mm
    Glume keel
    NA
    Glume relative length
    NA
    Glume shape
    NA
    Glume veins
    NA
    Glumes per spikelet
    0
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branch length
    4–10 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 branches coming off the lowest stem node
    2–4
    Inflorescence crowding
    the panicle is somewhat to very spread out, with clearly-evident branches
    Inflorescence length
    100–300 mm
    Inflorescence length to width ratio
    1.4–2.5
    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
    70–120 mm
    Inforescence position
    • the spikelets are mainly carried at the end of the stem
    • the spikelets are mainly found at the nodes, in the axils of leaves, along the stem
    Lemma awn base
    NA
    Lemma awn coiled
    NA
    Lemma awn length
    0 mm
    Lemma awn number
    the lemma has no awn
    Lemma awn orientation
    NA
    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 V-shaped if you cut across the midpoint
    Lemma hairs
    • the lemma has fine hairs between the veins
    • the lemma is hairless between the veins
    Lemma keel hairs
    the keel of the lemma is rough, or has fine hairs
    Lemma marginal vein hairs
    the marginal vein of the lemma has fine hairs on it
    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
    Lower glume length
    0 mm
    Lower glume relative length
    NA
    One or more florets
    there is one floret per spikelet
    Palea length
    4.2–5 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 length
    0 mm
    Spikelet axis tip
    there is no extension of the spikelet axis beyond the tip of the spikelet
    Spikelet disintegration
    NA
    Spikelet length
    4–6.5 mm
    Spikelet number per node
    0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet position
    the spikelets emerge mainly from the upper halves of the inflorescence branches
    Spikelet shape
    the spikelets are elliptic (widest in the middle, tapering to the ends) in profile
    Spikelet width
    1.3–1.7 mm
    Spikelets per panicle branch
    3–8
    Spikelets spiny
    the spikelets do not appear spiny
    Tip of glume
    NA
    Upper glume length
    0 mm
    Upper glume relative length
    NA
    Upper glume shape
    NA
  • Fruits or seeds

    Seed length
    2–3.5 mm
  • Growth form

    Horizontal rooting stem
    no
    Lifespan
    the plant lives more than two years
    Rhizomes
    yes
    Roots
    the plant has rhizomes (horizontal underground stem with roots growing from it)
  • Leaves

    Basal leaves
    the plant has few or no leaves coming from the base of the flowering stem
    Leaf auricles
    the leaves do not have auricles
    Leaf basal lobe hairy
    NA
    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
    15–30 cm
    Leaf blade texture
    the leaf blade is rough and sandpapery
    Leaf blade width
    5–15 mm
    Leaf ligule length
    0.5–1 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 no hairs on the surface of the leaf sheath
  • Place

    Habitat
    • aquatic
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of wetlands
    • in lakes or ponds
    • meadows or fields
    • shores of rivers or lakes
    • swamps
  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes have hairs that stand out at a shallow angle, or they curve downwards
    Plant height
    35–150 cm
    Roots at lower stem nodes
    yes
    Stem hairs
    the stem has hairs on it
    Stem orientation
    the stems trail at the base, but turn upwards at the tips
    Stem spacing
    the stems grow singly or a few together (they may form diffuse colonies)
    Stem thickness at base
    1–3 mm

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

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

1.  Leersia oryzoides (L.) Sw. N

rice cut grass. Homalocenchrus oryzoides (L.) Pollich; Phalaris oryzoides L. • CT, MA, ME, NH, 
 RI, VT. Shorelines, low areas in fields, open swamps, ditches, pools, beaver flowages.

Native to North America?

Yes

Sometimes confused with

Leersia virginica:
panicle with one branch per node and spikelets 2.9-4.1 mm long (vs. L. oryzoides, with a panicle with 2 branches at some nodes and spikelets 4-7.5 mm long).

Synonyms

  • Homalocenchrus oryzoides (L.) Pollich
  • Phalaris oryzoides L.

Family

Poaceae

Genus

Leersia