Index of Species Information

SPECIES:  Juncus roemerianus


SPECIES: Juncus roemerianus
AUTHORSHIP AND CITATION : Uchytil, Ronald J. 1992. Juncus roemerianus. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

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


SPECIES: Juncus roemerianus
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 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).


SPECIES: Juncus roemerianus
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 raccoon, 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 OTHER 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].


SPECIES: Juncus roemerianus
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


SPECIES: Juncus roemerianus
FIRE ECOLOGY OR ADAPTATIONS : Black rush survives fire by sending up new growth from surviving underground rhizomes after aboveground plant portions have been consumed. 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


SPECIES: Juncus roemerianus
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 : The Research Project Summary Vegetative response to fire exclusion and prescribed fire rotation on 2 Maryland salt marshes provides information on prescribed fire and postfire response of plant community species, including black rush, that was not available when this species review was written. 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. Salt marshes 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].


SPECIES: Juncus roemerianus
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] 9. Faulkner, Samuel P.; de la Cruz, Armando A. 1982. Nutrient mobilization 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] 11. 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] 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 p. [16324] 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 North Carolina Press. 1183 p. [7606] 23. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 24. Smith, Robert H. 1942. Management of salt marshes on the Atlantic Coast of the United States. Transactions, 7th North American Wildlife Conference. 7: 272-277. [14505] 25. Stout, J. P. 1984. The ecology of irregularly flooded salt marshes of the northeastern Gulf of Mexico: a community profile. Biol. Rep. 85(7.1). Washington, DC: U.S. Department of the Interior, Fish & Wildlife Service. [18064] 26. 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] 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 p. [10362] 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 Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT; RWU 4403 files. 7 p. [20090]