Slender Bulrush

Schoenoplectus heterochaetus (Chase) Soják

Scirpus heterochaetus spikelets
Troy Weldy

Class
Monocotyledoneae (Monocots)
Family
Cyperaceae (Sedge Family)
State Protection
Endangered
Listed as Endangered by New York State: in imminent danger of extirpation in New York. For animals, taking, importation, transportation, or possession is prohibited, except under license or permit. For plants, removal or damage without the consent of the landowner is prohibited.
Federal Protection
Not Listed
State Conservation Status Rank
S2
Imperiled in New York - Very vulnerable to disappearing from New York due to rarity or other factors; typically 6 to 20 populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines.
Global Conservation Status Rank
G5
Secure globally - Common in the world; widespread and abundant (but may be rare in some parts of its range).

Summary

State Ranking Justification

There are 4 verified occurrences, 8 historical occurrences.

Conservation and Management

Habitat

Habitat

Most occurrences of Slender Bulrush in New York occur in emergent marshes along slow-moving creeks or rivers, often at their mouths, in water depths of up to a meter (New York Natural Heritage Program 2011). Fresh, often calcareous marshes and lakes, often emergent in water to 1.5 m (FNA 2002). Margins of freshwater lakes and streams (Gleason & Cronquist 1991). Calcareous or other basic deadwaters, shores and swamps (Fernald 1970).

Associated Ecological Communities

  • Deep emergent marsh (guide)
    A marsh community flooded by waters that are not subject to violent wave action. Water depths can range from 6 in to 6.6 ft (15 cm to 2 m). Water levels may fluctuate seasonally, but the substrate is rarely dry, and there is usually standing water in the fall.
  • Shallow emergent marsh (guide)
    A marsh meadow community that occurs on soils that are permanently saturated and seasonally flooded. This marsh is better drained than a deep emergent marsh; water depths may range from 6 in to 3.3 ft (15 cm to 1 m) during flood stages, but the water level usually drops by mid to late summer and the soil is exposed during an average year.

Associated Species

  • Acer rubrum
  • Agrostis gigantea (red-top)
  • Alisma gramineum (grass-leaved water-plantain)
  • Asclepias incarnata
  • Boehmeria cylindrica (false nettle)
  • Bolboschoenus fluviatilis (river bulrush)
  • Brasenia schreberi (water-shield)
  • Butomus umbellatus (flowering-rush)
  • Calystegia sepium (hedge bindweed)
  • Cephalanthus occidentalis (buttonbush)
  • Cornus amomum
  • Dulichium arundinaceum
  • Eleocharis palustris (common spike-rush)
  • Elodea canadensis (Canada waterweed)
  • Fallopia japonica
  • Heteranthera dubia (water star-grass)
  • Impatiens capensis (spotted jewelweed, spotted touch-me-not)
  • Juncus effusus
  • Lycopus americanus (American bugleweed, American water-horehound)
  • Lythrum salicaria (purple loosestrife)
  • Najas flexilis (common water-nymph, common naiad)
  • Nuphar variegata (common yellow pond-lily, common spatter-dock)
  • Phalaris arundinacea (reed canary grass)
  • phleum pratense
  • Polygonum amphibium
  • Pontederia cordata (pickerelweed)
  • Potamogeton illinoensis (Illinois pondweed)
  • Rumex verticillatus (swamp dock)
  • Sagittaria latifolia (common arrowhead)
  • Salix x rubens
  • Sambucus racemosa (red elderberry)
  • Schoenoplectus acutus
  • Schoenoplectus pungens
  • Schoenoplectus tabernaemontani (soft-stemmed bulrush)
  • Solanum dulcamara (bitter-sweet nightshade)
  • Sparganium eurycarpum (giant bur-reed)
  • Trapa natans (water-chestnut)
  • Typha angustifolia (narrow-leaved cat-tail)
  • Typha latifolia (wide-leaved cat-tail)
  • Typha x glauca
  • Vallisneria americana (water-celery, tape-grass)
  • Zizania aquatica

Range

New York State Distribution

Scattered but mostly east and west of Adirondacks.

Identification Comments

Identifying Characteristics

Distinguishing characteristics: culms slender; inflorescence panicle with ascending to spreading very slender smooth to barely scabrous rays; bractlets whitish-brown, glabrous; spikelets mostly solitary, peduncled, rather few flowered, pale brown to drab or whitish-green, lance-acuminate to slenderly ellipsoid, acute to subacuminate, 0.75-2.3 cm long; scales glabrous, firm or subcoriaceous, much exceeding the achenes; bristles 2-4 (mostly 2), fragile, unequal, shorter than the achene; style 3-cleft; achenes unequally trigonous (twice as broad as thick). Best life stage for ID: in fruit. Characteristics needed to ID: mature achenes.

Similar Species

Scirpus acutus Muhl. has stouter stems; the inflorescence panicle is stiffer with relatively fewer rays; the spikelets are mostly in glomerules; scales are deep brown or reddish and more or less viscid-pubescent; the flowers are bicarpellate and achenes plano-convex, or occasionally some tricarpellate and unequally trigonous. Scirpus validus Vahl. stems are soft and easily crushed between the fingers; the inflorescence tends to be more open with drooping rays; spikelets are smaller (seldom over 1 cm); the scales are deep brown or reddish, about as long as the achenes; achenes are plano-convex.

Best Time to See

Flowers in June, fruits in July to early August.

  • Flowering
  • Fruiting

The time of year you would expect to find Slender Bulrush flowering and fruiting in New York.

Slender Bulrush Images

Taxonomy

Slender Bulrush
Schoenoplectus heterochaetus (Chase) Soják

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Monocotyledoneae (Monocots)
        • Order Cyperales
          • Family Cyperaceae (Sedge Family)

Synonyms

  • Scirpus heterochaetus Chase

Additional Resources

References

Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://newyork.plantatlas.usf.edu/, Albany, New York

Links

About This Guide

Information for this guide was last updated on: August 9, 2011

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Schoenoplectus heterochaetus. Available from: https://guides.nynhp.org/slender-bulrush/. Accessed March 28, 2024.