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| ## knotgrass {#knotgrass .Title-Header}                               |
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| *Paspalum distichum* L.                                               |
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| Plant Symbol = PADI6                                                  |
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Contributed by: USDA NRCS Louisiana State Office, National Plant Data
Center, & the Grazing Land Conservation Initiative-South Central Region

### 

## Alternative Names

Eternity grass, Fort Thompson grass, ginger grass, joint grass, joint
paspalum, saltene, salt jointgrass, salt-water couch grass, salt-water
paspalum, seashore paspalum, and turfgrass. Synonyms of the scientific
name are *Digitaria paspaloides*, *Paspalum distichum* var. *indutum*,
and *Paspalum paspaloides.* Some botanists consider *Paspalum distichum*
and *Paspalum vaginatum* as one species because they are similar in
appearance and are found in similar habitats. However, the second glume
at the base of the spikelet is hairy for *Paspalum distichum*.

## Uses

*Livestock:* Knotgrass is valuable forage in areas of high salinity. It
is recommended that knotgrass is

lightly grazed and given a rest period of

approximately 2 ½ to 3 months because the rooted

stolons are often floating. It can be made into hay but is not suitable
for silage.

*Ornamental Landscaping:* Knotgrass is used in golf course turfs and
lawns. ![](media/image2.jpeg){width="2.422222222222222in"
height="3.8618055555555557in"}

*Wildlife*: It is grazed by many mammals and is considered a substantial
source of food for ducks in Louisiana marshes.

*Erosion:* Knotgrass is recommended in the restorations of wetlands,
marshes, beaches, and stream banks.

*Conservation Practices*: Knotgrass, because of its growth habit,
potentially has application when established with certain conservation
practices; however, conservation practice standards vary by state. For
localized information, consult your local NRCS Field Office. NRCS
practices include the following: 327-Conservation Cover; 342-Critical
Area Planting; 386-Field Border; 390-Riparian Herbaceous Cover;
393-Filter Strip; 512-Pasture and Hay Planting; 550-Range Planting;
560-Access Road; 562-Recreation Area Improvement; 643-Restoration and
Management of Declining Habitats; 644-Wetland Wildlife Habitat
Management; 647-Early Successional Habitat Development/Management;
656-Constructed Wetland; 657-Wetland Restoration; 658-Wetland Creation;
659-Wetland Enhancement.

## Status

Consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status, such as, state noxious status
and wetland indicator values.

## Description

*General*: Grass Family (Poaceae). It is a perennial which may be
creeping or growing in clumps. The creeping stems produce roots at the
nodes in which flowering stems emerge. The culms are firm and range in
heights up to 1½ feet. The nodes on creeping stems are often pubescent
whereas the nodes on the mat-forming stems are glabrous. The sheaths are
loose and glabrous to pubescent. The blades are flat and taper to an
inrolled apex. They are 2 to 6 inches long and about 1 inch wide. The
flowering stem bears terminal digital racemes in 2's or 3's, that are up
to 3 inches long. Axes are winged and glabrous with thin, dry margins.
The spikelets are solitary and straw-purple in color. The first glume is
rarely present. The second glume and sterile lemma are glabrous and
3-nerved. The grain is yellowish and oblong to ellipsoid.

## Distribution

Knotgrass is found in both wet and well-drained areas. It frequents
meadows, marshes, and ditches. It can also be found in cultivated or
disturbed areas, and bordering wooded areas. It is located throughout
the southeast United States, Arkansas, Texas, Oklahoma, and in the
western United States. It is native to Louisiana. For current
distribution, consult the Plant Profile page for this species on the
PLANTS Web site.

## Establishment

*Adaptation*: Knotgrass can tolerate high salinity and a waterlogged
environment. It has no tolerance of shade. New growth starts in early
March and it stays green until the first frost.

Knotgrass reproduces from rhizomes, stolons, and seeds. It can be easily
established by sowing stolons in damp holes. If planted in water,
knotgrass will remain green throughout the year.

Knotgrass may flower throughout the year. The seeds may be gathered;
however, they require a period of dormancy. The seeds yield their
highest germination when temperatures are between 82 to 95º F and when
they receive about 16 hours of light. Ripening can be sped up with dry
storage at 122º F. Also, scarring the seeds with acid may increase
germination.

It is not recommended to mix knotgrass seeds with cool season grass
seeds. In parts of the United States where cool season grasses dominate,
the warm season grasses can be taken over because they develop slower
than the cool season grasses. It is also recommended that seed not be
moved more than 300 miles north, 100 miles east or west, or 200 miles
south of its point of origin.

## Management

Tilling knotgrass on a dry surface will increase stolons to root and
encourage a denser sod. Grazing also increases knotgrass. It withstands
burning if water is above soil surface. The rhizomes enable knotgrass to
survive fire. It sometimes can be troublesome by blocking irrigation
ditches. In direct-seeded rice it is a serious weed that grows
vigorously under favorable conditions. Check with the local extension
service for recommended herbicides. Knotgrass has no known pests or
problems.

## Cultivars, Improved and Selected Materials (and area of origin)

Contact your local NRCS Field Office. Common seed and container plants
are readily available from a number of growers, wholesalers, and
retailers of native seed. Contact your local Natural Resources
Conservation Service (formerly Soil Conservation Service) office for
more information. Look in the phone book under "United States
Government." The Natural Resources Conservation Service will be listed
under the subheading "Department of Agriculture."

## References

Hitchcock, A.S. 1950. *Manual of the grasses of the United States*. USDA
Miscellaneous Publication No 200. Agricultural Research Administration,
Washington, D.C. Pp. 603-604.

U.S. Department of Agriculture 1999. *Southern wetland flora: field
office guide to plant species: Paspalum distichum*. (Version 12APR99).
\<http://www.npwrc.usgs.gov/resource/1999/soutflor/species/2/paspdist.htm\>.
USDA Natural Resources Conservation Service, South National Technical
Center, Fort Worth, Texas. Northern Prairie Wildlife Research Center
Home Page, Jamestown, North Dakota.

USDA, NRCS 2003. *The PLANTS database*. \<http://plants.usda.gov\>.
001106. National Plant Data Center, Baton Rouge, Louisiana.

## Prepared By

# *Selena Dawn Newman*

USDA, NRCS, Louisiana Plant Materials Program

# *Maraya Gates*

Formerly USDA, NRCS, National Plant Data Center

## Species Coordinator

# *Mike Materne*

Louisiana State University, Agricultural Center, Baton Rouge, Louisiana

Edited 06dec00 jsp;05feb03ahv; 10aug03 jsp; 060802 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](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

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*To file a complaint of discrimination write USDA, Director, Office of
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