CPC National Collection Plant Profile

Scirpus ancistrochaetus

William Larkin

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CPC National Collection Plant Profile

Scirpus ancistrochaetus

Common Names: 
barbed-bristle bulrush, Northeastern bulrush, Northern bulrush
Growth Habit: 
CPC Number: 


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Scirpus ancistrochaetusenlarge
Photographer: William Larkin
Image Owner: New England Wildflower Society

Scirpus ancistrochaetus is Fully Sponsored
Primary custodian for this plant in the CPC National Collection of Endangered Plants is: 
Elizabeth J. Farnsworth contributed to this Plant Profile.

Scirpus ancistrochaetus

This leafy bulrush in the sedge family is currently known only from about 60 populations scattered from New Hampshire and Massachusetts, south to West Virginia. An obligate wetland plant, Scirpus ancistrochaetus grows in shallow water along the margins of sinkhole ponds (in the south), beaver ponds, sandplain depressions, backwater ponds in river floodplains, a boggy marsh, and even a wet depression on a mountaintop rocky bald -- broadly described as "low areas of hilly country" (Massachusetts Natural Heritage and Endangered Species Program 1992). Sandstone or sand appears to be its favored substrate, and sites tend to share the common feature of a fluctuating water level. Although it is everywhere rare (with populations mostly under a few dozen stems), several new discoveries have been made with increased inventorying and an improved understanding of the habitat features with which it is commonly associated.

Research and Management Summary:
Several recent field studies of Scirpus ancistrochaetus have revealed much about its ecology and habitat associations. Extensive field surveys have turned up a number of new populations, and monitoring efforts are ongoing in a number of states.

Plant Description:
Scirpus ancistrochaetus is a tall (to 1.2 m) bulrush with leaves from 3 to 8 mm wide. Its short, woody rhizomes give rise to a flowering stem in in mid-June to mid-July, with a drooping flower head bearing dark, chocolate-brown florets with broad bracts. Each floret has six rigid bristles ending in recurved, sharp-pointed barbs -- the source of its Latin name, ancistrochaetus, meaning "hooked hairs." The 1.1-1.3 mm-long dry, one-seeded fruits (achenes) ripen in late summer.

Distribution & Occurrence

State Range
New York
West Virginia
State Range of  Scirpus ancistrochaetus
  Scirpus ancistrochaetus is described from a variety of wetlands along its extensive range. In the north, the species is found most commonly on the edge of shallow beaver ponds (Royte and Lortie 2000) where water levels vary depending on animal activity. One population occurs on an inland sandplain in Massachusetts, in a depression that periodically fills with groundwater. In the south, the taxon occurs often in sinkhole ponds that form in sandstone bedrock at intermediate elevations around 200 to 500 meters (somewhat higher elevations in the Virginias). Plants at all sites occur around the margins of ponds in 8 to 40 cm of standing water (in wet years). In a study comparing Pennsylvania wetlands that support Scirpus ancistrochaetus with nearby ponds that did not, researchers found that Scirpus ponds were typically larger (> 400 square meters), more free of forest canopy cover, higher in exchangeable sodium (> 7 ppm), and higher in pH (Lentz and Dunson 1999).

Associated plant species reported from sites with the bulrush include: Dulichium arundinaceum, Ilex verticillata, Scutellaria lateriflora, Boehmeria cylindrica, Apocynum sp., Rosa palustris, Lyonia ligustrina, Vaccinium angustifolium, Acer rubrum, Nyssa sylvatica, Quercus alba, Pinus strobus, Nuphar advena, Cephalanthus occidentalis, Lemna minor, Carex crinita, Carex lupuliformis, Carex lurida, Carex lupulina, Carex canescens, Carex vesicaria, Carex stricta, Eleocharis obtusa, Eleocharis quadrangulata, Scirpus cyperinus, Scirpus pedicellatus, Triadenum virginicum, Glyceria canadensis, Glyceria septentrionalis, Glyceria acutiflora, Osmunda cinnamomea, Leersia oryzoides, Potamogeton pulcher, Polygonum amphibium, Sium suave, Scutellaria lateriflora, Bidens frondosa, Polygonum punctatum, Nuphar variegatum, Schoenoplectis tabernaemontani, Sparganium androcladum, Hypericum virginicum, Galium tinctorum, and Ludwigia palustris (Schuyler 1962, Bartgis 1992, MANHESP 1992, Lentz and Dunson 1999, Royte and Lortie 2000, NatureServe 2001).

  Scirpus ancistrochaetus is found in the Connecticut River Valley of New Hampshire and Vermont, and north-central Massachusetts. Although once reported from New York and Quebec, the species is now considered historic in both places. The species next pops up in interior Pennsylvania, Maryland, Virginia, and West Virginia (Schuyler 1962, USFWS 1991 & 1993, Royte and Lortie 2000, NatureServe 2001).

Number Left
  Precise numbers of populations of Scirpus ancistrochaetus are unknown, and others may yet be discovered. Approximately 50 to 60 sites are recorded. Because plants are clonal and population sizes also vary widely among years, estimating the global population is problematic.


Global Rank:  
Guide to Global Ranks
Federal Status:  
Guide to Federal Status
Recovery Plan:  

State/Area Protection
  State/Area Rank Status Date  
  Canada N4 6/11/2001  
  Maryland S1 E 4/30/2001  
  Massachusetts S1 E 11/29/2001  
  New York SX U 4/1/2001  
  Pennsylvania S3 PE 2/9/2001  
  Quebec SH  
  United States N3 2/27/1996  
  Vermont S2 E 3/1/2000  
  Virginia S2 LE 3/1/2001  
  West Virginia S1 E 6/1/2000  

Conservation, Ecology & Research

Ecological Relationships
  Plants emerge from underground rhizomes in May (the new year's seedlings typically begin to germinate in March (NatureServe 2001).

Flowering occurs from mid-June to mid-July across the range of the species.

Hybridization has been observed between S. ancistrochaetus and S. hattorianus in the wild; in fact, Schuyler (1962, 1967) suggested that the intermediate, co-occurring species, S. atrovirens, may have arisen evolutionarily from a back-cross hybridization of these taxa.

Plants are likely to be wind-pollinated.

Seeds mature in late summer to fall, and have been observed germinating on the parent plant (NatureServe 2001). Plants may also reproduce vegetatively by proliferating along rhizomes or by initiating new shoots off decumbent stems (Bartgis 1992); however, the relative contributions of sexual and asexual reproduction to population growth are not currently understood.

The bristly seeds may be dispersed by animals or by water (Lentz and Dunson 1999).

Seeds can remain viable in storage for several years (W. E. Brumback, New England Wild Flower Society, personal communication; Lentz and Johnson 1998), but their longevity in natural seedbanks has not been determined.

Herbivores are unknown, but mammals such as deer, beaver, and bear have been noted to disturb the soil around Scirpus ancistrochaetus stands (Lentz and Dunson 1999).

  As articulated by NatureServe (2001) and U. S. Fish and Wildlife Service (1991, 1993), threats include:

Run-off from upland sources that contaminates wetlands where Scirpus ancistrochaetus is found
Logging (particularly at one site in Maryland)
Road construction that impacts wetlands directly or changes hydrology
Beavers that change hydrology in Scirpus ancistrochaetus wetlands (especially at one site in Vermont)
Trampling by all-terrain vehicles
Habitat conversion to support residential, industrial, and agricultural development
Fire (especially at one site in Pennsylvania)

Current Research Summary
  Kendra Lentz of Pennsylvania State University has conducted extensive studies on: habitat characteristics; light and nutrient requirements; effects of simulated herbivory and plant competition on plant growth; seed germination; and flood-tolerance for Scirpus ancistrochaetus (Lentz 1998, Lentz and Cipollini 1998, Lentz and Johnson 1998, Lentz 1999, Lentz and Dunson 1999)

Additional seed germination trials have been undertaken at the New England Wild Flower Society (Framingham, Massachusetts). Fresh and dried seed both germinate well after a period of moist cold (in refrigeration or storage outdoors); this finding is corroborated by Lentz and Johnson (1998), who obtained optimal success with dried and stratified seed. Flowering plants have been cultivated for seed. Scirpus ancistrochaetus currently grows at the NEWFS Garden.

Current Management Summary
  Volunteer task forces of the New England Plant Conservation Program (New England Wild Flower Society) and other conservation organizations regularly monitor Scirpus ancistrochaetus in New England.

Rodney L. Bartgis (The Nature Conservancy, West Virginia) has surveyed for the taxon in West Virginia and Maryland (Bartgis 1992) and maintains a regular monitoring program.

G. C. Tucker (Eastern Illinois University) reports a new site for Scirpus ancistrochaetus in Canada (Tucker, in review, Rhodora)

Tom Rawinski of Massachusetts Audubon Society (Lincoln, Massachusetts) has surveyed for Scirpus ancistrochaetus in Virginia

Joshua Royte (The Nature Conservancy, Brunswick, Maine) and John Lortie (Woodlot Alternatives, Topsham, Maine) have surveyed for the taxon in New Hampshire and found several new occurrences (Royte and Lortie 2000).

The Nature Conservancy has conducted systematic surveys for the taxon in Pennsylvania and New Hampshire

Research Management Needs
  More extensive surveys in suitable habitat to find new occurrences of Scirpus ancistrochaetus
Studies to assess the relative contribution of sexual and asexual reproduction to sustaining population viability and possible roles of inbreeding depression
Experimental field studies to determine how water levels and other ecological factors can be manipulated to promote establishment and expansion of populations
Studies of inter-breeding dynamics with other Scirpus species.

Ex Situ Needs
  Field studies to determine the extent to which Scirpus ancistrochaetus forms natural seed banks


Books (Single Authors)

Gleason, H.A.; Cronquist, A. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Bronx: The New York Botanical Garden.

Gray, A.; Fernald, M.L. 1987. Gray's manual of botany: a handbook of the flowering plants and ferns of the central and northeastern United States and adjacent Canada. Portland, Or.: Dioscorides Press. 1632p.

Rhoads, A.F.; Klein, W.M., Jr. 1993. The vascular flora of Pennsylvania: Annotated checklist and atlas. Philadelphia, PA: American Philosophical Society. 636p.

Electronic Sources

MANHESP. (1993). Massachusetts Endangered Plants Fact Sheets. Massachusetts Natural Heritage and Endangered Species Program; Division of Fisheries and Wildlife, Westborough, Massachusetts. http://www.state.ma.us/dfwele/dfw/nhesp/nhfactplt.htm. Accessed: 2002.

NatureServe. (2008). NatureServe Explorer: An online encyclopedia of life [web application]. [Internet].Version 7.0. NatureServe, Arlington, Virginia. http://www.natureserve.org/explorer. Accessed: (June 17, 2008).

PDCNR. (2002). Threatened and Endangered Species of Pennsylvania. [Web site] The Pennsylvania Department of Conservation and Natural Resources. http://www.dcnr.state.pa.us/wrcf/plants.htm. Accessed: 2002.

USGS. (2002). Status of Listed Species and Recovery Plan Development. [Web site] USGS: Norther Prairie Wildlife Research Center. http://www.npwrc.usgs.gov/resource/distr/others/recoprog/plant.htm. Accessed: 2002.

WVDNR. (1998). Endangered Species Profiles. West Virginia Department of Natural Resources. http://www.dnr.state.wv.us/wvwildlife/endangered.htm. Accessed: 2002.

Journal Articles

Lentz, K.A. 1998. Ecology of Endangered Northeastern Bulrush, Scirpus ancistrochaetus Schuyler. Dissertation Abstracts International. 59-06, Section: B: 2546.

Lentz, K.A. 1999. Effects of intraspecific competition and nutrient supply on the endangered northeastern bulrush, Scirpus ancistrochaetus Schuyler (Cyperaceae). American Midland Naturalist. 142, 1: 47-54.

Lentz, K.A.; Cipollini, D.F. 1998. Effect of light and simulated herbivory on growth of endangered northeastern bulrush, Scirpus ancistrochaetus Schuyler. Plant Ecology. 139, 1: 125-131.

Lentz, K.A.; Dunson, W.A. 1998. Water level affects growth of endangered northeastern bulrush, Scirpus ancistrochaetus Schuyler. Aquatic Botany. 60, 3: 213-219.

Lentz, K.A.; Dunson, W.A. 1999. Distinguishing characteristics of temporary pond habitat of endangered northeastern bulrush, Scirpus ancistrochaetus. Wetlands. 19, 1: 162-167.

Lentz, K.A.; Johnson, H.A. 1998. Factors affecting germination of endangered northeastern bulrush, Scirpus ancistrochaetus Schuyler (Cyperaceae). Seed Science and Technology. 26, 3: 733-741.

Royte, J.L.; Lortie, J.P. 2000. New records for Scirpus ancistrochaetus in New Hampshire. Rhodora. 102, 910: 210-213.

Schuyler, A.E. 1962. A new species of Scirpus in the northeastern U.S. Rhodora. 64: 43-49.

Schuyler, A.E. 1963. Notes on Five Species of Scirpus in Eastern North America. Bartonia. 33: 1-6.

Schuyler, A.E. 1967. A taxonomic revision of North American leafy species of Scirpus. Proceedings of the Academy of Natural Sciences, Philadelphia. 119: 295-323.

USFWS. 1976. Proposed Endangered Status for 1700 U.S. Plants. Federal Register. 41: 24523-24572.

USFWS. 1990. Endangered and threatened wildlife and plants; proposed endangered status for Scirpus ancistrochaetus (Northeastern Bulrush). Federal Register. 55: 46963-46968.

USFWS. 1990. Listing Proposals--November 1990. Endangered Species Technical Bulletin. 15, 12: 4.

USFWS. 1991. Determination of endangered status for Scirpus ancistrochaetus (northeastern bulrush). Federal Register. 56, 88: 21091-21096.


Bartgis, R.L. 1989. Status Survey Summary: Scirpus ancistrochaetus in Maryland and West Virginia. Prepared for The Nature Conservancy.

Mitchell, R.S.; Sheviak, C.J. 1981. Rare Plants of New York State. Bull. No. 445. Albany, N.Y.: New York State Museum. University of the State of New York. p.96.

Program, Vermont Natural Heritage. 1985. Vermont status report, Scirpus ancistrochaetus Schuyl. Unpublished.

Rawinski, T.J. 1989. Northeastern bulrush (Scirpus ancistrochaetus) in Virginia: results of the 1989 status survey. Unpublished report to U.S. Fish & Wildlife Service, Region 5.

Rawinski, T.J. 1990. Final status survey report: distribution and abundance of northeastern bulrush (Scirpus ancistrochaetus). Unpublished report to U.S. Fish & Wildlife Service, Region 5.

Reschke, C.; Clemants, S. 1985. Field survey report on Putnam, Mountain Swamp. Unpublished.

Smith, T. 1985. Element global status summary, Scirpus ancistrochaetus. Unpublished.

Smith, T.; Schuyler, A.E. 1985. Field survey report on Rosecrons Bog. Unpublished.

Smith, T.; Schuyler, A.E.; Wilkinson, A. 1985. Field survey report on Stafford Bald. Unpublished.

Smith, T.L. 1990. 1989 U.S. Fish & Wildlife Service candidate plant species survey for eastern Pennsylvania. Unpublished.

Sorrie, B.; LeBlond, R. 1989. Field survey report on Green Pond. Unpublished.

Thompson, E. 1985. Vermont status report, 1985, Scirpus ancistrochaetus Schuyl. Unpublished.

Thompson, E.; Rawinski, T. 1985. Field survey report on Bulrush Meadow. Unpublished.

Thompson, E.H. 1990. Vermont status report, Scirpus ancistrochaetus Schuyler. Unpublished.

USFWS. 1993. Northeastern Bulrush (Scirpus ancistrochaetus) Recovery Plan. Hadley, Massachusetts: U.S. Fish and Wildlife Service. p.68.

  This profile was updated on 3/4/2010
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