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Wildlife, Animals, and Plants
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Introductory
SPECIES: Juncus roemerianus | Black Rush
ABBREVIATION :
JUNROE
SYNONYMS :
NO-ENTRY
SCS PLANT CODE :
JURO
COMMON NAMES :
black rush
black needlerush
needlerush
needle rush
needle grass
TAXONOMY :
The currently accepted scientific name of black rush is Juncus
roemerianus Scheele. [11,22]. There are no recognized varieties,
subspecies, or forms.
LIFE FORM :
Graminoid
FEDERAL LEGAL STATUS :
No special status
OTHER STATUS :
NO-ENTRY
COMPILED BY AND DATE :
Ronald Uchytil, May 1992
LAST REVISED BY AND DATE :
NO-ENTRY
AUTHORSHIP AND CITATION :
Uchytil, Ronald J. 1992. Juncus roemerianus. In: Remainder of Citation
DISTRIBUTION AND OCCURRENCE
SPECIES: Juncus roemerianus | Black Rush
GENERAL DISTRIBUTION :
Black rush is primarily restricted to coastal marshes and estuaries of
the South Atlantic and Gulf Coast states. Its distribution is
continuous from New Jersey to southern Florida, and westward to
southeastern Texas. Scattered outlying populations also occur in
Connecticut, New York, Mexico, and the Caribbean Islands [4].
ECOSYSTEMS :
FRES16 Oak - gum - cypress
FRES41 Wet grasslands
STATES :
AL CT DE FL GA LA MD MS NJ NY
NC SC TX VA MEXICO
ADMINISTRATIVE UNITS :
ASIS BICY CAHA CALO CUIS EVER
GUIS
BLM PHYSIOGRAPHIC REGIONS :
NO-ENTRY
KUCHLER PLANT ASSOCIATIONS :
K072 Sea oats prairie
K073 Northern cordgrass prairie
K078 Southern cordgrass prairie
K080 Marl - everglades
K090 Live oak - sea oats
K092 Everglades
K105 Mangrove
K113 Southern floodplain forest
SAF COVER TYPES :
101 Baldcypress
102 Baldcypress - tupelo
106 Mangrove
SRM (RANGELAND) COVER TYPES :
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES :
Black rush is one of the dominant marsh species of the southern Atlantic
and Gulf coasts. In northwest Florida, it has been estimated that 60
percent of the salt marshes are covered with monospecific stands of this
species [19]. In many situations, monospecific stands of smooth
cordgrass (Spartina alterniflora) form a seaward zone that borders black
rush. The boundary between these communities is usually distinct and
abrupt [4,19].
Black-rush-dominated communities have been separated into three
generalized categories based upon elevation and soil salinity influences
[25]. The number of species associated with black rush tends to
increase as water salinity decreases [4]. The three categories of black
rush marsh are presented below:
(1) Saline marsh, which experiences little dilution of tidal waters.
Associates include smooth cordgrass, saltmeadow cordgrass (S. patens),
giant cordgrass (S. cynosuroides), saltgrass (Distichlis spicata),
glasswort (Salicornia spp.), Olney threesquare (Scirpus americanus), and
saltmarsh bulrush (Scirpus robustus).
(2) Brackish marsh, where tidal waters are routinely diluted before
flooding the marsh. Associates include smooth cordgrass, giant
cordgrass, saltmeadow cordgrass, sealavender (Limonium caroliniana),
Olney threesquare, and common arrowhead (Sagittaria latifolia).
(3) Intermediate marsh, which is transitional between brackish and
freshwater marsh. Associates include common reed (Phragmites
australis), sawgrass (Cladium jamaicense), softstem bulrush (Scirpus
validus), and Virginia iris (Iris virginica).
VALUE AND USE
SPECIES: Juncus roemerianus | Black Rush
WOOD PRODUCTS VALUE :
NO-ENTRY
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Habitat: Food and cover are abundant in black-rush-dominated coastal
marshes because plant density and net primary productivity are high.
However, few animal species have adapted to the rigorous conditions
created by the alternating terrestrial and aquatic environment. Those
that have adapted are abundant; thus animal production is high, but
diversity is low [19]. Mammal residents include the nutria, muskrat,
rice rat, and marsh rabbit. Other mammals, such as the racoon, cotton
rat, mink, and cotton mouse, are common visitors but prefer more
terrestrial, less frequently flooded marsh [19,25]. Black-
rush-dominated marsh is the primary nesting and feeding habitat of the
clapper rail and seaside sparrow. Additionally, more than 60 species of
birds use habitats within this marsh type at least seasonally [25].
Food: Black rush's value as wildlife food is limited. Its small seeds
are eaten only rarely by ducks [17]. Although generally not a preferred
muskrat or nutria food, black rush leaves and rhizomes can be an
important food source for these animals in local areas [6,18].
Black rush is generally avoided by cattle [2].
PALATABILITY :
NO-ENTRY
NUTRITIONAL VALUE :
NO-ENTRY
COVER VALUE :
Black rush presumably provides good hiding cover for the birds and small
mammals that inhabit and visit coastal marshes.
The long-billed marsh wren, clapper rail, and seaside sparrow nest
primarily in black rush [19,25]. Rice rats, which prey on bird eggs,
also nest in black rush, usually in the vicinity of nesting long-billed
marsh wrens and seaside sparrows [19]. The black duck and occasionally
other waterfowl also nest in black rush [17].
VALUE FOR REHABILITATION OF DISTURBED SITES :
Black rush may be useful for shoreline stabilization and for vegetating
dredged spoils, but direct planting is rarely justified because of
erratic transplanting success. For shoreline stabilization, it is
easier to establish other species and allow black rush to naturally
invade where it is best adapted [14]. However, Stout [25] points out
that black rush is very slow to naturally colonize spoil islands in
Mississippi, often taking 10 years. It is estimated that it would take
16 to 35 years for black rush to colonize spoils and form a closed stand
[25].
OTHER USES AND VALUES :
NO-ENTRY
MANAGEMENT CONSIDERATIONS :
Black rush was effectively controlled with aerial applications of
various herbicides in Florida. Plants were most susceptible to spraying
just before and during flowering. Multiple cuttings also provided
effective black rush control [20].
Black rush is an increaser in coastal marshes grazed by cattle [2,24].
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Juncus roemerianus | Black Rush
GENERAL BOTANICAL CHARACTERISTICS :
Black rush is a tufted, coarse and rigid, rhizomatous, perennial
grasslike herb. It tolerates a wide range of environments, which
greatly affects its density and growth habit. Where soil water salinity
is low, black rush is often very robust, with leaves reaching over 7
feet (2.1 m) in height, while in hypersaline areas the plants are
dwarfed, often less than 1 foot (0.3 m) tall [5]. Both tall and short
stature plants occur in most salt marshes, with the tallest plants
occurring near open water (low soil salinity) and the shortest near land
(high soil salinity because of longer and more frequent periods of
exposure) [25]. Conversely, plant density increases farther inland. In
northwest Florida, stem density and height varied with elevation as
follows [25]:
low marsh upper marsh high marsh
(deep water) (shallow water)
density (shoots/m2) 1660 2097 4719
live shoot density 885 993 1692
dead shoot density 776 1164 3029
mean height (inches/cm) 40/102 35/88 31/78
Rhizomes average about 0.35 inch (9 mm) in diameter, and are primarily
located within 4 inches (10 cm) of the soil surface [5,28].
RAUNKIAER LIFE FORM :
Geophyte
Helophyte
REGENERATION PROCESSES :
Black rush reproduces both sexually and asexually. Existing stands are
maintained through vigorous rhizome growth, while new stands are
established via seed dispersal and seedling establishment. Black rush
reproduction biology presented below is summarized from Eleuterius
[3,6].
Seed production and dispersal: Two flowering types occur in black rush.
Plants produce either perfect flowers only, or pistillate flowers only.
Pistillate-flowered plants produce more and higher viability seeds than
perfect-flowered plants. Seeds from a single inflorescence are shed
simultaneously.
Germination and seedling establishment: Black rush seeds are highly
viable. In Mississippi, germination averaged about 75 percent and 60
percent for seeds from pistillate and perfect flowers, respectively.
Seeds remain viable for more than 1 year and may germinate any time
germination requirements for moisture and light are met. The seeds are
light dependent; thus few seedlings occur on muddy sediments where seeds
are easily covered. Sandy, wet, vegetation-free substrates provide the
best germination sites because seeds are not easily covered, and if they
are covered, sufficient light for germination is able to penetrate the
thin sand covering. In fact black rush seedlings are almost always
restricted to barren, sandy areas. They are almost never found in
established black rush stands or other marsh types. Germination
decreases with increasing salinity, and is inhibited by salinities above
15 parts per thousand. In Mississippi, germination which leads to
successful plant establishment occurs from November to April. Spring
and summer germinants are less likely to survive because surface
sediments dry during the summer and fall resulting in seedling death.
SITE CHARACTERISTICS :
Black rush inhabits coastal tidal marshes and may extend as far as 10 to
15 miles inland along river estuaries [6]. It typically occurs in
nearly pure stands, forming a distinct vegetation zone that may be
several hundred yards to several miles wide [25]. This zone usually
encompasses a narrow elevational range. In Mississippi, the black rush
zone covered an elevational range of only 0.7 feet (0.2 m), from 1.7 to
2.4 feet (0.54-0.75 m) above mean low water [6,25].
Salinity: Black rush tolerates a wide range of salinities. It has a
greater tolerance to salt than most plants inhabiting brackish or saline
marshes. High-salinity soils tend to favor black rush by removing less
salt-tolerant competitors. Under laboratory conditions, it grows best
in freshwater, but its natural inland distribution is limited by low
salinity. Along Mississippi coastal rivers, black rush is replaced
inland by sawgrass or tree-covered swamp as salinity decreases. Growth
in freshwater habitats may be restricted by soil organisms which feed on
black rush rhizomes [6].
Soil: Black rush grows on a wide variety of soil types, ranging from
almost pure sand to fine silt and clay mixtures. It grows in highly
organic soils, including peat. In black rush stands in Mississippi,
soil pH ranged from 4.5 to 7.0 [6].
SUCCESSIONAL STATUS :
Obligate Climax Species
Black rush is considered a climax species [4].
SEASONAL DEVELOPMENT :
In contrast with associated marsh plants which have a single annual
flush of growth, black rush produces new shoots and leaves throughout
the year [7]. Flowering in several states is as follows [3,21]:
southern Florida - March
southeastern Louisiana - March and April
Mississippi - late January to May, peak in March
North Carolina - January to June
FIRE ECOLOGY
SPECIES: Juncus roemerianus | Black Rush
FIRE ECOLOGY OR ADAPTATIONS :
Black rush survives fire by sending up new growth from surviving
underground rhizomes after aboveground plant portions have been
consumed.
POSTFIRE REGENERATION STRATEGY :
Rhizomatous herb, rhizome in soil
FIRE EFFECTS
SPECIES: Juncus roemerianus | Black Rush
IMMEDIATE FIRE EFFECT ON PLANT :
The effects of fire on black rush mortality vary with water depth and
soil moisture. On flooded sites, and on sites with exposed but
saturated soils, fire may consume aboveground plant portions but leave
underground regenerative structures unharmed. When a marsh floor is
completely dry, however, fire can burn deep into the soil, consuming the
rhizomes and killing entire stands [24].
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
A black-rush-dominated coastal marsh in Mississippi was burned in late
February during low tide when the marsh surface was exposed. The
immediate effect was the removal of 71 percent of the vegetative cover.
Most culms were only partially burned. Incomplete combustion of black
rush was apparently due to the formation of a steam layer along the
marsh floor and/or the high moisture content of the culms near the
sediment [9].
PLANT RESPONSE TO FIRE :
In coastal Mississippi black-rush-dominated marshes, net primary
productivity over a 3-year period was greater on burned than on unburned
marsh. However, black rush recovered more slowly than did species of
cordgrass. Three years after burning, total black rush biomass was
lower than before burning [13].
Myers [20] reported that winter burning increased Olney threesquare when
it occurred as a competing subdominant with black rush. In nearly pure
stands of black rush, however, burning did not change the species
composition of the marsh.
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
NO-ENTRY
FIRE MANAGEMENT CONSIDERATIONS :
Prescribed burning on a 4- to 5-year rotation can be used to maintain
the vigor of black rush marshes. Burning more frequently would be
difficult because of insufficient fuel. It takes more than 3 years for
total biomass to reach preburn levels [13].
In southern Florida salt marshes, adequate wind is needed when
conducting a prescribed burn in order to push the fire over open water.
If standing water is not present, soil moisture should exceed 65 percent
on areas underlain by peat, to prevent its ignition. Saltmarshes
bordered by mangrove (Rizophora mangle, Avicennia germinans) are easy to
burn because the mangrove acts as a fire break. Where fresh and
saltwater marsh merge, fire can be confined to the salt marsh by
knocking a swath through the fuel at the vegetative boundary and setting
a headfire from that line [27].
REFERENCES
SPECIES: Juncus roemerianus | Black Rush
REFERENCES :
1. 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]
2. 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]
3. Eleuterius, Lionel N. 1975. The life history of the salt marsh rush,
Juncus roemerianus. Bulletin of the Torrey Botanical Club. 102(3):
135-140. [16946]
4. Eleuterius, Lionel N. 1976. The distribution of Juncus roemerianus in
the salt marshes of North America. Chesapeake Science. 17(4): 289-292.
[17805]
5. Eleuterius, Lionel N. 1976. Vegetative morphology and anatomy of the
salt marsh rush, Juncus roemerianus. Gulf Research Reports. 5(2): 1-10.
[17804]
6. Eleuterius, Lionel N. 1984. Autecology of the black needlerush Juncus
roemerianus. Gulf Research Reports. 7(4): 339-350. [17803]
7. Eleuterius, Lionel N.; Caldwell, John D. 1981. Growth kinetics and
longevity of the salt marsh rush Juncus roemerianus. Gulf Research
Reports. 7(1): 27-34. [17806]
8. Eyre, F. H., ed. 1980. Forest cover types of the United States and
Canada. Washington, DC: Society of American Foresters. 148 p. [905]
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following winter fires in an irregularly flooded marsh. Journal of
Environmental Quality. 11(1): 129-133. [16155]
10. 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]
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southeastern United States: Monocotyledons. Athens, GA: The University
of Georgia Press. 712 p. [16906]
12. Hackney, Courtney T.; De LaCruz, Armando A. 1978. The effects of fire on
the prod. and species comp. of 2 St. Louis Bay, MS tidal marshes
dominated by J. roemerianus and S. cynosuroides, resp. Journal of the
Mississippi Academy of Sciences. 23: 109. [14573]
13. Hackney, Courtney T.; de la Cruz, Armando A. 1981. Effects of fire on
brackish marsh communities: managememt implications. Wetlands. 1: 75-86.
[14534]
14. Knutson, P. L.; Woodhouse, W. W., Jr. 1983. Shore stabilization with
salt marsh vegetation. Special Rep. 9. U.S. Department of Defence, Army
Corps of Engineers. Microfiche. [18063]
15. 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]
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. Martin, Alex C.; Erickson, Ray C.; Steenis, John H. 1957. Improving duck
marshes by weed control. Circular 19 (Revised). Washington, DC: U.S.
Department of the Interior, Bureau of Sport Fisheries and Wildlife. 60
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18. Milne, Robert C.; Quay, Thomas L. 1967. The foods and feeding habits of
the nutria on Hatteras Island, North Carolina. Proceedings, Annual
Conference of Southeastern Association of Game and Fish Commissions. 20:
112-123. [15302]
19. Montague, Clay L.; Wiegert, Richard G. 1990. Salt marshes. In: Myers,
Ronald L.; Ewel, John J., eds. Ecosystems of Florida. Orlando, FL:
University of Central Florida Press: 481-516. [17395]
20. Myers, Kent E. 1956. Management of needlerush marsh at the
Chassahowitzka Refuge. Proceedings Annual Conf. Southeast. Assoc. Game
and Fish Comm. 9: 175-177. [17807]
21. Penfound, W. T.; Hathaway, Edward S. 1938. Plant communities in the
marshlands of southeastern Louisiana. Ecological Monographs. 8(1): 3-56.
[15089]
22. Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of
the vascular flora of the Carolinas. Chapel Hill, NC: The University of
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geography. Oxford: Clarendon Press. 632 p. [2843]
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of the United States. Transactions, 7th North American Wildlife
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25. Stout, J. P. 1984. The ecology of irregularly flooded salt marshes of
the northeastern Gulf of Mexico: a community profile. Biol. Rep.
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National list of scientific plant names. Vol. 1. List of plant names.
SCS-TP-159. Washington, DC. 416 p. [11573]
27. Wade, Dale; Ewel, John; Hofstetter, Ronald. 1980. Fire in South Florida
ecosystems. Gen. Tech. Rep. SE-17. Asheville, NC: U.S. Department of
Agriculture, Forest Service, Southeastern Forest Experiment Station. 125
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28. de la Cruz, Armando, A.; Hackney, Courtney T. 1977. Energy value,
elemental composition, and productivity of belowground biomass of a
Juncus tidal marsh. Ecology. 58(5): 1165-1170. [17847]
29. Stickney, Peter F. 1989. Seral origin of species originating in northern
Rocky Mountain forests. Unpublished draft on file at: U.S. Department of
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Index
Related categories for Species: Juncus roemerianus
| Black Rush
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