|barbed-bristle bulrush, Northeastern bulrush, Northern bulrush|
|Elizabeth J. Farnsworth|
The following Participating Institutions are custodians for this species in the CPC National Collection:
New England Wild Flower Society
The conservation of Scirpus ancistrochaetus is fully sponsored.
Elizabeth J. Farnsworth contributed to this Plant Profile.
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.
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
- New York
- West Virginia
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).
|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.|
Conservation, Ecology & Research
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).
Run-off from upland sources that contaminates wetlands where Scirpus ancistrochaetus is found
Logging (particularly at one site in Maryland)
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.
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
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.
Rhoads, A.F.; Klein, W.M., Jr. 1993. The vascular flora of Pennsylvania: Annotated checklist and atlas. Philadelphia, PA: American Philosophical Society. 636p.