Plant Fact Sheet
United States Department of Agriculture-Natural Resources Conservation Service
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National Plant Data Center <http://npdc.usda.gov>
RICE CUTGRASS
Leersia oryzoides (L.) Sw.
Plant Symbol = LEOR
Contributed by: USDA NRCS Plant Materials
Center, Corvallis, Oregon
Alternate Names
Plant synonyms include Homalocenchrus oryzoides
(L.) Pollich, and Phalaris oryzoides L. Another
common name is sickle grass.
Uses
Rice cutgrass is valuable for wildlife habitat
improvement, wetland restoration, and erosion
control in ditches and other watercourses. The seeds
are an important food source for waterfowl, small
mammals, and shorebirds. Ducks pull up and
consume underground stems (rhizomes). Dense
colonies provide cover and habitat for fish, reptiles,
and amphibians. The forage produced is highly
palatable. This plant’s creeping rhizomes and
spreading habit are good for sediment stabilization
along the immediate shorelines of streams and lakes.
Tolerant of highly acidic conditions (pH=3), the
species is being studied for use in constructed
wetlands and the treatment of acid mine drainage. It
may have potential for vegetated drainage ditches
that mitigate agricultural runoff, including pesticides.
Status
Please consult the PLANTS Web site and your State
Department of Natural Resources for this plant’s
current status (e.g. threatened or endangered species,
state noxious status, and wetland indicator values).
Dale Darris
USDA NRCS Corvallis PMC
Description and Adaptation
Rice cutgrass is a native cool season grass that grows
and flowers comparatively late in summer. The seed
ripens in late August to early October, more typical
of a warm season species. This short to medium
lived perennial spreads by scaly, underground
rhizomes and often forms dense colonies. The stalks
(stems) are upright to sprawling, velvety at the nodes
(joints), and 90 to 125 (150) cm tall. Leaf blades are
7 to 30 cm long, 6 to 15 (20) mm wide, and yellow-
green in color. They have a coarse or rough upper
surface and are lined with tiny teeth along the
margins. The flowerhead (panicle) is open, often
drooping, and 10 to 20 cm long. Some panicles
remain enclosed within the lower leaf sheaths and
release seeds upon decay of the stem. The seed hull
is covered with minute bristles that readily cling to
clothing or fur for dispersal. Rice cutgrass is
widespread across southern Canada and most of the
United States. It is also found in the warmer parts of
Europe.
Key to identification: This grass is quickly identified
by running a hand through it. The sharp leaves can
cut flesh and tear weaker clothing. They are abrasive
and sandpapery to the touch. Seeds resemble rice
and are not easily confused with other native grasses.
The spikelets hang in a single row creating a 1-sided
appearance to each panicle branch. Rice cutgrass
can easily be confused with two other species of
Leersia commonly found in North America. Consult
botanical keys for proper ID.
Relative abundance in the wild: Rice cutgrass is
occasional to very abundant. Once stands are
located, seed is easily stripped by hand. Retention of
seed is fair at best. Seed shatters (drops) readily at
maturity.
Adaptation: Rice cutgrass can be found in a variety
of wet, sunny, and partially shaded sites. However, it
is most common near streams, ponds, or beaver areas,
and in ditches, canals, or freshwater marshes. This
species thrives best in nutrient rich mud and slow
moving or stagnant water. Seedlings may not survive
submergence for more than 2 to 3 days, while mature
plants easily tolerate seasonal to permanent flooding.
Reportedly, this grass can grow in standing water up
to 0.5 (15 cm), 1 ft (30 cm) or 3 ft (1 meter) deep.
It can be found in other habitats where soils are
saturated at or near the surface year round or
continuously moist in summer. It occasionally co-
exists with reed canarygrass (Phalaris arundinacea)
on wetter sites, but is much less broadly adapted.
Soils may range from acid to alkaline [pH (3) 5.1 to
8.8] sands, silts, loams, or clays. For natural
regeneration, rice cutgrass needs bare mud and an
open vegetative structure created by seasonal
inundation and regular disturbance.
Establishment
Rice cutgrass
seed possesses
physiological
dormancy
requiring a 180
to 270 day
period of cool,
moist
stratification
(moist chilling).
Gentle
scarification
(abrasion of the
seed coat after
hull removal)
may improve germination as well. Late summer or
early fall seeding is recommended. Seeds will
germinate the following spring. There are
approximately 360,000 seeds/lb (+/- 20%). A
seeding rate of 1 lb/acre of pure live seeds will result
in 8 live seeds per square foot. Rarely sown alone
due to cost, it typically comprises 1 to 20% of a seed
mix. Rhizomes, rootstock, and container plants are
also used for establishment. A spacing of 1 to 3 feet
(30-90 cm) will achieve uniform ground coverage in
1 to 3 years respectively. Rhizomes should be
planted 2 to 5 inches (5-12 cm) deep.
Management
Plants develop relatively slowly in spring, becoming
most productive during the summer. The seed
matures in late August or September and the plants
go dormant soon after (October-November). Stand
maintenance or proliferation requires adequate soil
fertility, regular flooding, and soil disturbance every
two to three years to create open areas. For wildlife
enhancement, this species is well suited to moist soil
management techniques (slow summer de-watering,
soil disking, etc.) applied to certain wetlands and
shallow water impoundments. In some cases,
disturbance and regeneration have been promoted by
grazing cattle.
Environmental Concerns
Rice cutgrass has a narrow ecological adaptation and
may not persist well. However, it is also a weed in
some situations, including commercial cranberry
beds (bogs) in the Pacific Northwest and Northeast.
It is sometimes considered a weed in the Southeast as
well. This species can form dense colonies to the
potential exclusion of other native marsh grasses and
herbs. However, under undisturbed conditions it is
regularly replaced by other species. The abrasive
leaves may cause skin injury.
Cultivars, Improved, and Selected Materials (and
area of origin)
Line drawing reprinted with permission,
Univ. of Wash. Press
Seed sources can be hard to locate for Oregon,
Washington, and California. Container plants and
rootstock are somewhat more common. It is readily
available in the Midwestern states from seed
producers and nurseries.
Prepared By:
Dale Darris and Amy Bartow, USDA NRCS Plant
Materials Center, Corvallis, Oregon.
Species Coordinator:
Dale Darris, USDA NRCS Plant Materials Center,
Corvallis, Oregon.
Edited: 21mar2006 jsp, 16sept2008 dcd; 080917 jsp
For more information about this and other plants, please contact
your local NRCS field office or Conservation District, and visit the
PLANTS Web site<http://plants.usda.gov
> or the Plant Materials
Program Web site <http://Plant-Materials.nrcs.usda.gov
>
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