Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: Eleocharis wolfii has a broad distribution throughout the central and eastern United States. The range of the species includes the following states: Arkansas, Colorado, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Minnesota, Mississippi, Missouri, Nebraska, North Dakota, Ohio, Oklahoma, Tennessee, Texas, and Wisconsin (Martin 1993, Robertson and Phillippe 1992, Smith 1988). The species is cited as being adventive in New York (Young 1992a, Young 1992b). The following state and provinces were also included in the range for this species in various publications: Alabama (TNC HO 1992), Alberta (Gleason and Cronquist 1991, GPFA 1986, Gleason 1952), southern California (OH NHP 1992), northern Mexico (OH NHP 1992), Saskatchewan (Kartesz 1993, Fernald 1970, Steyermark 1963), and South Dakota (Kartesz 1993, Van Bruggen 1985). No verified records from these states are known.
Robertson and Phillippe (1992) identified the differences between similar Eleocharis taxa in Illinois. The differences between E. wolfii, E. elliptica var. compressa (E. compressa) and E. acicularis appear below:
Eleocharis wolfii: Flattened blue-green, 1 mm wide culms; very slender rhizome; scales 2.5-3.0 mm long; and white achenes with longitudinal ridges.
E. elliptica var. compressa: Compressed dark-green culm, a thick rigid rhizome and brown to yellow reticulate achenes.
E. acicularis: Green, 0.1-0.5 mm wide culms and spikelet scales 1.5-2.2 mm long. Achenes nearly identical to E. wolfii.
Eleocharis wolfii is also very similar to E. compressa and E. rostellata, which are other rhizomatous spikerushes with flattened culms. These species can be separated by observing mature spikelets and achenes (OH NHP 1992).
Eleocharis wolfii can be differentiated from E. compressa by the following characteristics: In E. wolfii the achenes are twice as long as they are wide, nearly circular in cross-section, gray, with several longitudinal ridges and numerous fine cross-lines, and the spikelet has a basal scale which is often floriferous. In E. compressa, the achenes differ in that they are two-thirds to fully as wide as they are long, having three sides (triangular in cross-section), with the basal scale of the spikelet usually being empty (Gleason and Cronquist 1991).
E. rostellata differs from E. wolfii and E. compressa by having a tubercle (a projection on top of the achene) which merges with the achene to form a beak, instead of forming a distinct apical cap as in the other two species (Gleason and Cronquist 1991).
Catalog Number: US 57000
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): J. Wolf
Year Collected: 1874
Locality: Canton., Fulton, Illinois, United States, North America
- Isotype: Gray, A. 1874. Proc. Amer. Acad. Arts. 10: 77.
Comments: Eleocharis wolfii occurs in marshes, wet to wet-mesic prairies, wet margins of lakes, rivers, ponds and creeks, wet ditches, sandy roadsides, mud flats and ephemerally wet flatwoods (Dobberpuhl 1992, Gleason and Cronquist 1991, Ueno et al. 1989, Great Plains Flora Association 1986, Fernald 1970, Steyermark 1963, Gleason 1952). Individuals grow best and reproduce only in relatively open, sunlit habitats that retain moisture throughout the growing season (Homoya 1994).
In Illinois, E. wolfii is apparently restricted to natural or artificial ephemeral pools in open prairies or Quercus palustris sections of Q. stellata flatwoods on river terraces (Robertson and Phillippe 1992, Mohlenbrock 1975, University of Minnesota Herbarium (MIN)). Prairie sites are characterized by poorly drained soils of deep gray silt loam or gray silt loam on tight clay (Robertson and Phillipe 1992). At prairie sites, typical associates include Apocynum cannabinum, Carex annectens, C. bicknellii, Eleocharis verrucosa, Galium obtusum, Helianthus mollis, Potentilla simplex and Solidago canadensis (Robertson and Phillippe 1992). At Quercus stellata flatwoods sites, E. wolfii grows upright in ephemeral pools (as in prairie settings), but is decumbent on tussocks in shaded depressions. Soils are poorly drained okaw silt loam, cape silty clay loam or hurst silt loam. Typical associates include Carex annectens, C. bicknellii, C. caroliniana, Cinna arundinacea, Eleocharis verrucosa, Galium obtusum, Isoetes melanopoda, Quercus bicolor and Q. palustris (Robertson and Phillippe 1992).
Occupied habitat in Indiana includes ephemerally wet flatwoods and wet sand prairies, both with acidic substrates (Homoya 1992). Deam (1940) listed "low, flat clearings" for specimens he collected in Jefferson County. Specimens at the Morton Arboretum (MOR) from Hoosier Prairie (Lake County) were collected from a small dense pond and sedge meadow. Associates in the former habitat included Cyperus rivularis, C. strigosus, Eleocharis obtusa, Polygala sanguinea, Panicum agrostoides, Echinochloa crus-galli, Poa pratensis, Juncus acuminatus, J. dudleyi and Rotala armosior. The latter habitat possessed sandy soil with some humus, with Typha, Carex sp., Eleocharis, Juncus, Spartina and Alisma as associated (Robertson and Phillippe 1992).
Two specimens collected from Emmet County, Iowa, in 1882 and 1909 list habitat as wet ground and prairies (University of Minnesota Herbarium (MIN)). The species was also collected in the southern part of the state in the 1950's, but no habitat information was available (Pearson 1993).
Eleocharis wolfii was last found in Kansas in 1960. Occupied habitats are thought to include floodplain swales, wet ditches, pond margins and similar habitats (Freeman 1992b). Historic collections have come from a floodplain swale along the Neosho River and a flooded roadside ditch (Freeman 1992a, KS NHI 1992).
Habitat in Louisiana consists of prairies with high levels of sodium in the subsoil. Ruderal habitats include roadsides and cemeteries (McInnis 1992).
In Minnesota, habitat of E. wolfii is poorly known (Coffin and Pfannmuller 1988). It seems to be restricted to wetlands in the prairie region of the state. Historic records describe the habitat as "mud flats near stream" and "moist places" (MN NHP 1992, Coffin and Pfannmuller 1988, University of Minnesota Herbarium (MIN)).
Eleocharis wolfii habitat in Missouri consists of bottomland prairie swales and wet prairies (Ladd 1993, MO NHI 1993, Holt et al. 1974, Steyermark 1963). Associated plant species at one historical site include Equisetum arvense, Fimbristylis caroliniana, Symphoricarpos spp. and Typha latifolia (MO NHI 1993, Smith 1993).
In New York, a collection record from Nassau County on Long Island described the historic habitat as an open swamp (Young 1992b).
Historic records from North Dakota describe habitat as a roadside ditch and an undeveloped area of a college campus (since developed) (Lenz 1993b, University of Minnesota Herbarium (MIN)).
In Ohio, habitat is moist, open areas, pond margins, cattle pastures and fields (Cusick 1992, OH NHP 1992).
No extant occurrences are known for E. wolfii in Wisconsin. A single collection was made from habitat described as a wet, sandy roadside. Associated plant species included Aletris farinosa, Drosera rotundifolia, Juncus spp., Rhynchospora spp., Spiraea tomentosa, Viola lanceolata and Xyris torta. Other possible associates included Asclepias tuberosa, Hypericum kalmianum, Platanthera clavellata and Triadenum fraseri (Dobberpuhl 1992).
Specimens from Tennessee at the University of Tennessee Herbarium (TENN) were collected from a number of habitats, including a moist depression in an oak barren with Platanthera flava, an edge of a pool within a swamp, a wet opening in a meadow, calcareous soil in a wet meadow and the margin of Tullahoma Creek (Robertson and Phillippe 1992). The species is not considered to be rare in the state (Pyne 1994).
In Texas, E. wolfii populations are scattered throughout the state. The species appears to be relatively rare, although it becomes locally common in the Panhandle and northern portions of the state. Large populations are also known from the Edwards Plateau region. The species occupies wet pools and open, wet ditches usually on clay soils. In the Edwards Plateau, it occurs in alluvial silt clay over granitic bedrock. Associates include Eleocharis montevidensis in the Edwards Plateau. Elsewhere, Carex oklahomensis, C. annectens, C. fissa, C. brevior and Panicum hians are associates (Jones 1994).
Eleocharis wolfii is locally common in Oklahoma where it is found in wet areas over clay soils. In southeastern Oklahoma it is frequently associated with Carex oklahomensis, which yields to C. fissa to the west. Other associates include C. annectens, C. brevior and Panicum hians (Jones 1994).
A single collection of E. wolfii from Colorado was made in 1939 from the Black Forest in El Paso County. It is not known from what habitat the specimen was collected, but the Black Forest is dominated by Pinus ponderosa on the hilltops, Quercus gambelii on upper slopes and tall and shortgrass prairie on the lower hillsides (Kettler 1993).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 to >300
Comments: The number of element occurrences for this species is largely unknown. Though widespread, the species has likely been overlooked and undercollected. Recently, inventory efforts in Missouri have turned up 27 occurrences and it is believed that this species is more common than once believed, due to undercollection; there is one historic occurrence known in Missouri. Further, in Missouri this species is showing up in most of their prairies and wetlands across the state (pers. comm. T. Smith). Additionally, search efforts in Arkansas have lead to the discovery of 27 occurrences in the state (pers. comm. T. Witsell). There are extant, documented occurrences in Georgia (4), Illinois (22), Indiana (14), Minnesota (1) and Nebraska. Several new reports of this species in Nebraska have also been made (pers. comm. P. McKenzie). Other reports of extant populations Texas, Oklahoma (several), Louisiana (1-2). E. wolfii is considered sufficiently common to go untracked in Mississippi and in Tennessee (occurs in 5 counties).
The flowering and fruiting season for Eleocharis wolfii is May- July (Steyermark 1963, Fernald 1970, Mohlenbrock 1975, OH NHP 1992). The species remains recognizable into late September (Young 1992b). This plant commonly forms mats as it grows (KS NHI 1992).
Eleocharis wolfii requires high light levels in order to produce viable seed (Homoya 1994). In the absence of adequate light, plants become weakened and elongated, with achenes being aborted before reaching maturity. Conversely, over-exposed sites frequently dry out quickly and also result in poor reproduction.
All of the Eleocharis species have leaves which are reduced to basal bladeless sheaths and culms which function as photosynthetic organs (Ueno et al. 1989).
Life History and Behavior
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Reasons: Wide range, but apparently rare throughout much of its northern range. Eleocharis wolfii is poorly known and may be overlooked due to insufficient inventory. This species has been recently discovered at many sites in Missouri and Arkansas, and is generally believed to be more common than specimen collections indicate (pers. comm. T. Smith). It is threatened by the loss of its native wetland and grassland habitat, however, it is found in a wide variety of habitats.
Global Short Term Trend: Relatively stable to decline of 30%
Comments: This species is apparently rare and infrequent throughout much of its wide range, although it has likely been overlooked and undercollected. Although the species probably suffered significant declines over the past 150 years, declines in Eleocharis wolfii are likely to continue due to wetland drainage, especially in agricultural areas. Loss of wetlands has been as great as 90 percent in some areas (Coffin and Pfannmuller 1988).
Comments: The loss of native grassland and wetland habitat is probably the greatest threat to E. wolfii. These habitats are being lost to agricultural activities such as the drainage of land for cultivation and the creation of pastures, and to numerous forms of development, including roadway development and home construction (Kettler 1993, Ladd 1993, Lenz 1993b, MO NHI 1993, Dobberpuhl 1992, Homoya 1992, McInnis 1992, Robertson and Phillippe 1992, Coffin and Pfannmuller 1988). Highway alignment activities in Illinois threatened a population in 1992, but the state Department of Transportation was persuaded to avoid the site (Robertson and Phillippe 1992).
In prairie areas, E. wolfii is threatened by the overgrowth of woody vegetation through succession. With the loss of the natural fire regime, prairie habitats have been significantly threatened by woody encroachment. Encroachment of exotic plant species is a potential threat at some extant sites. Soil compaction and associated physical disturbance of habitat from long-term, high-intensity cattle grazing is a major threat to populations of E. wolfii located within prairie habitat (Cusick 1992).
In forested sites, clearing of timber and resultant drainage for cultivation and other potential uses has destroyed much of the habitat over time. This continues to be a serious threat (MO NHI 1993, Homoya 1992, OH NHP 1992, Robertson and Phillippe 1992).
Herbicide application is a potential threat, particularly to populations occurring along highway or railroad right-of-ways. In 1992, one population along a railroad right-of-way in Illinois was seriously damaged by herbicide application. Approximately 90% of the above-ground stems were killed (Robertson and Phillippe 1992).
Recent discoveries (2006) of this species in Arkansas have turned up in a wide variety of habitats, all of which are sensitive or declining (pers. comm. T. Witsell).
Restoration Potential: The restoration potential of this species is unknown to date. Very few extant populations are known throughout the range of the species and no known attempt has been made to address this issue. Given the apparent scarcity of the species in many areas, this information may be needed.
Preserve Selection and Design Considerations: Preserve designs should encompass sufficient area to protect the hydrological integrity of the site. Designs should encompass sufficient buffer to allow for prescribed fire and other management activities, thereby reducing threats from smoke drift and other hazards to persons and property outside of the managed area. Buffer areas should also be added to increase protection of populations from outside influences such as herbicide drift, etc.
Management Requirements: Management requirements for Eleocharis wolfii are poorly known. Maintenance of natural hydrological regimes and implementation of prescribed fire management in prairie habitats are perhaps the two most important requirements of this species. Specific details regarding these and other management options are not known.
Management Programs: No management programs are in place for Eleocharis wolfii throughout its range.
Monitoring Programs: No monitoring programs are known to be in effect for Eleocharis wolfii.
Management Research Programs: Kathy Martin, Botanist, U.S. Fish and Wildlife Service is completing a federal status report for E. wolfii. Contact: Kathy Martin, U. S. Fish and Wildlife Service, 1500 East Capitol Avenue, Bismarck, North Dakota 58501. Telephone: (701) 250-4414.
Biological Research Needs: A characterization of the habitat and natural communities of Eleocharis wolfii needs to be made (Dobberpuhl 1992, Freeman 1992b). Without a much-enhanced idea of what constitutes typical E. wolfii habitat, management plans would be difficult or impossible to write.
Studies are also needed to look at the life history and population trends (phenology, reproduction, etc.) of the species (Dobberpuhl 1992, Lenz 1993b). This information is crucial in determining the proper tools, guidelines and goals of management and restoration efforts.
In addition, an investigation into beneficial management practices would aid future management decisions (Dobberpuhl 1992, Lenz 1993b).
Comments: Range distribution maps for Eleocharis wolfii can be found in the following sources: Arkansas (Smith 1988), Illinois (Robertson and Phillippe 1992), Indiana (Deam 1940), Minnesota (Ownbey and Morley 1991, Coffin and Pfannmuller 1988), Missouri (Steyermark 1963), North America (Coffin and Pfannmuller 1988), United States (Robertson and Phillippe 1992).
Illustrations of the species can be found in: Coffin and Pfannmuller (1988), Fernald (1970), Steyermark (1963) and Gleason (1952).
Relevance to Humans and Ecosystems
Stewardship Overview: Threats to Eleocharis wolfii habitat include agricultural conversion and associated activities, construction activities, woody plant encroachment, excessive grazing, herbicide application and destructive recreational activities. Management needs for E. wolfii include the protection of natural hydrological regimes and implementation of prescribed fire management in prairie habitats. Monitoring of E. wolfii populations should be completed on a regular basis to track the status of extant occurrences with respect to on-going management activities. Monitoring should track population size, flowering and fruiting success, recruitment, changes in occupied habitat over time and hydrological fluctuations. Surveys should be made to locate additional extant populations and to relocate historic occurrences. Research needs include the characterization of E. wolfii habitat, life history information, population trends, beneficial management practices, reproductive biology, ecology and population demographics of this species.
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