Index of Species Information
SPECIES: Paspalum distichum
Introductory
SPECIES: Paspalum distichum
AUTHORSHIP AND CITATION :
Snyder, S. A. 1992. Paspalum distichum. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station,
Fire Sciences Laboratory (Producer). Available:
https://www.fs.usda.gov/database/feis/plants/graminoid/pasdis/all.html [].
ABBREVIATION :
PASDIS
SYNONYMS :
Paspalum vaginatum Sw.
Paspalum paspalodes (Michx.) Scribn.
SCS PLANT CODE :
PADI6
PAVA
COMMON NAMES :
knotgrass
seashore paspalum
salt jointgrass
turfgrass
TAXONOMY :
The currrently accepted scientific name for knotgrass is Paspalum
distichum L. (Gramineae) [9]. Although many authorities distinguish the
closely related species P. vaginatum, Godfrey and Wooten [11] consider
this distinction unwarranted. Paspalum vaginatum and P. distichum will
be treated as a single species for the purpose of this report.
LIFE FORM :
Graminoid
FEDERAL LEGAL STATUS :
No special status
OTHER STATUS :
NO-ENTRY
DISTRIBUTION AND OCCURRENCE
SPECIES: Paspalum distichum
GENERAL DISTRIBUTION :
Knotgrass is common throughout the southeastern states; it occurs as far
north as Massachusetts and south into Mexico and South America. It is
also narrowly distributed throughout the Southwest and continues north
through California to coastal Oregon and Washington, and central Idaho
[9].
ECOSYSTEMS :
FRES41 Wet grasslands
FRES42 Annual grasslands
STATES :
AL AZ AR CA DE FL GA ID HI LA
MD MA MS NV NJ NM NC OK OR SC
TN TX UT VA WA MEXICO
BLM PHYSIOGRAPHIC REGIONS :
1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
7 Lower Basin and Range
14 Great Plains
KUCHLER PLANT ASSOCIATIONS :
K049 Tule marshes
K072 Sea oats prairie
K088 Fayette prairie
SAF COVER TYPES :
NO-ENTRY
SRM (RANGELAND) COVER TYPES :
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES :
NO-ENTRY
MANAGEMENT CONSIDERATIONS
SPECIES: Paspalum distichum
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Knotgrass is a valuable duck food in the marshes of Louisiana [3]. It
is also considered a good forage grass in Arizona [12].
PALATABILITY :
NO-ENTRY
NUTRITIONAL VALUE :
NO-ENTRY
COVER VALUE :
NO-ENTRY
VALUE FOR REHABILITATION OF DISTURBED SITES :
Knotgrass is sometimes used to revegetate eroded marshes in Louisiana
[14]. It is also used to rehabilitate overgrazed ranges in Arizona.
Results of this project have not yet been released [22]. In germination
tests, seeds were incubated at 82 to 95 degrees Fahrenheit (28-35 deg
C). Fourteen percent germinated in the dark, while 40 percent
germinated with 16 hours of light. Ripening can be sped up with dry
storage at 122 degrees Fahrenheit (50 deg C). Scarification with acid
can increase germination [10].
OTHER USES AND VALUES :
NO-ENTRY
OTHER MANAGEMENT CONSIDERATIONS :
Knotgrass increases in response to grazing [3]. It is useful as a soil
binder along streams but can sometimes be troublesome, as it chokes out
irrigation ditches [8,12,17].
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Paspalum distichum
GENERAL BOTANICAL CHARACTERISTICS :
Knotgrass is a native, perennial, rhizomatous graminoid [9]. Its culms
are 7 to 20 inches (0.2-0.6 m) high and are sometimes pubescent [17,18].
Usually two racemes are found at the end of the stem. Leaf blades are
flat and from 2 to 6 inches (5-15 cm) long. Rhizomes form dense,
extensive mats [5].
RAUNKIAER LIFE FORM :
Phanerophyte
Geophyte
REGENERATION PROCESSES :
Regeneration occurs mostly from the spreading and sprouting of rhizomes.
Creeping stems root at the nodes and give rise to flowering stems [8].
SITE CHARACTERISTICS :
Knotgrass is found along fresh and brackish marshes, coastal salt
marshes, ponds, ditches, shorelines, beaches, and dunes; and in
freshwater wetlands of the semiarid grasslands of the Southwest
[4,8,11,18]. Some associates include sea purslane (Sesuvium
portulacastrum), beach dropseed (Sporobolus virginicus), Mexican beach
peanut (Okenia hypogaea), railroad vine (Ipomoea pes-caprae), sea
lavender (Argusia gnaphalodes), beachberry (Scaevola plumieri), bay
cedar (Suriana maritima), cordgrass (Spartina spp.), muhly grass
(Muhlenbergia spp.), sedge (Carex spp.), horsetail (Equisetum spp.),
spikerush (Eleocharis spp.), rush (Juncus spp.), Olney bulrush (Scirpus
olneyi), slender wheatgrass (Elymus trachycaulus ssp. trachycaulus), and
johnsongrass (Sorghum halpense) [3,4,11,14].
SUCCESSIONAL STATUS :
Knotgrass replaces marshbay cordgrass (Spartina patens) and Olney
bulrush in Gulf Coast marshes where grazing has reduced these species.
Knotgrass is then replaced by "annuals and unpalatable forbs" [1].
Along the southern Florida coast south of Cape Canaveral, knotgrass
along with pink-flowered railroad vine may recolonize the upper beach
from the foredune after storm erosion [11].
SEASONAL DEVELOPMENT :
Knotgrass flowers and produces fruit between June and November [15,18].
FIRE ECOLOGY
SPECIES: Paspalum distichum
FIRE ECOLOGY OR ADAPTATIONS :
Rhizomes generally enable knotgrass to survive fire.
FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find Fire Regimes".
POSTFIRE REGENERATION STRATEGY :
Rhizomatous herb, rhizome in soil
FIRE EFFECTS
SPECIES: Paspalum distichum
IMMEDIATE FIRE EFFECT ON PLANT :
Fire probably topkills knotgrass.
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
NO-ENTRY
PLANT RESPONSE TO FIRE :
Knotgrass sprouts from rhizomes following fire [21].
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
Prescribed fires were conducted annually in northern Florida on sites
where Paspalum species were present in the understory. Some plots were
burned annually, some every second winter, some every third, some every
fourth, etc. through 12 winters. Annual and biennial burning maintained
the highest grass covers; cover declined sharply starting with fires
every third year [21].
FIRE MANAGEMENT CONSIDERATIONS :
Fire can be used to reduce litter and increase plant vigor and
production in grasses. Fire can also be used to maintain open
grasslands by preventing establishment of woody vegetation [21].
REFERENCES
SPECIES: Paspalum distichum
REFERENCES :
1. Allan, Philip F. 1950. Ecological bases for land use planning in Gulf
Coast marshlands. Journal of Soil and Water Conservation. 5: 57-62, 85.
[14612]
2. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals,
reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's
associations for the eleven western states. Tech. Note 301. Denver, CO:
U.S. Department of the Interior, Bureau of Land Management. 169 p.
[434]
3. Chabreck, Robert H. 1968. The relation of cattle and cattle grazing to
marsh wildlife and plants in Louisiana. Proceedings, Annual Conference
Southeastern Association of Game and Fish Commissioners. 22: 55-58.
[14503]
4. Cross, Anne Fernald. 1991. Vegetation of two southeastern Arizona desert
marshes. Madrono. 38(3): 185-194. [16107]
5. Duncan, Wilbur H.; Duncan, Marion B. 1987. The Smithsonian guide to
seaside plants of the Gulf and Atlantic Coasts from Louisiana to
Massachusetts, exclusive of lower peninsular Florida. Washington, DC:
Smithsonian Institution Press. 409 p. [12906]
6. Eyre, F. H., ed. 1980. Forest cover types of the United States and
Canada. Washington, DC: Society of American Foresters. 148 p. [905]
7. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others].
1977. Vegetation and environmental features of forest and range
ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of
Agriculture, Forest Service. 68 p. [998]
8. Godfrey, Robert K.; Wooten, Jean W. 1979. Aquatic and wetland plants of
southeastern United States: Monocotyledons. Athens, GA: The University
of Georgia Press. 712 p. [16906]
9. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific
Northwest. Seattle, WA: University of Washington Press. 730 p. [1168]
10. Huang, W. Z.; Hsiao, A. I. 1987. Factors affecting seed dormancy and
germination of Paspalum distichum. Weed Research. 27(6): 405-416.
[17412]
11. Johnson, Ann F.; Barbour, Michael G. 1990. Dunes and maritime forests.
In: Myers, Ronald L.; Ewel, John J., eds. Ecosystems of Florida.
Orlando, FL: University of Central Florida Press: 430-480. [17394]
12. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock,
Elizabeth. 1960. Arizona flora. 2d ed. Berkeley, CA: University of
California Press. 1085 p. [6563]
13. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation
of the conterminous United States. Special Publication No. 36. New York:
American Geographical Society. 77 p. [1384]
14. Lehto, Bruce; Murphy, Jeff. 1989. Effects of drawdown and water
management on a seriously eroded marsh. U.S. Fish and Wildlife Service:
Biological Report. 89(22): 164-169. [17337]
15. Lonard, Robert I.; Judd, Frank W. 1989. Phenology of native angiosperms
of South Padre Island, Texas. In: Bragg, Thomas B.; Stubbendieck, James,
eds. Prairie pioneers: ecology, history and culture: Proceedings, 11th
North American prairie conference; 1988 August 7-11; Lincoln, NE.
Lincoln, NE: University of Nebraska: 217-222. [14049]
16. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession
following large northern Rocky Mountain wildfires. In: Proceedings, Tall
Timbers fire ecology conference and Intermountain Fire Research Council
fire and land management symposium; 1974 October 8-10; Missoula, MT. No.
14. Tallahassee, FL: Tall Timbers Research Station: 355-373. [1496]
17. Mason, Herbert L. 1957. A flora of the marshes of California. Berkeley,
CA: University of California Press. 878 p. [16905]
18. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA:
University of California Press. 1905 p. [6155]
19. Raunkiaer, C. 1934. The life forms of plants and statistical plant
geography. Oxford: Clarendon Press. 632 p. [2843]
20. U.S. Department of Agriculture, Soil Conservation Service. 1982.
National list of scientific plant names. Vol. 1. List of plant names.
SCS-TP-159. Washington, DC. 416 p. [11573]
21. Vogl, Richard J. 1973. Fire in the southeastern grasslands. In:
Proceedings, annual Tall Timbers fire ecology conference; 1972 June 8-9;
Lubbock, TX. Number 12. Tallahassee, FL: Tall Timbers Research Station:
175-198. [8466]
22. Wolden, Lynn; Stromberg, Julie; Patten, Duncan; Richter, Holly. 1990.
Understory restoration in three riparian forest types. Restoration &
Management Notes. 8(2): 116-117. [13790]
23. Stickney, Peter F. 1989. Seral origin of species originating in northern
Rocky Mountain forests. Unpublished draft on file at: U.S. Department of
Agriculture, Forest Service, Intermountain Research Station, Fire
Sciences Laboratory, Missoula, MT; RWU 4403 files. 7 p. [20090]
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