Carex lupuliformis line drawing Harry Charles Creutzburg; CyperSedge website

Carex lupuliformis line drawing
Harry Charles Creutzburg; CyperSedge website

Monocotyledoneae (Monocots)
Cyperaceae (Sedge Family)
State Protection
Federal Protection
Not Listed
State Conservation Status Rank
Global Conservation Status Rank


Did you know?

This sedge can be searched for very late in the season as it tends to stay green into October and even early November. The spikelets are host to a fly parasite which may result in deformed fruits. The specific name is derived from the resemblance of its inflated fruits to hops (Humulus lupulus).

State Ranking Justification

There are 16 reported populations, but only seven of these have more than 25 plants. There are about 20 historical populations and these should be surveyed to determine if the plants are still present. Difficulty with keys/characters have led to misidentifications and the late ripening of fruit has likely limited the number of successful surveys for this plant. This plant has likely always been uncommon within New York as it has a limited distribution, specific habitat, and typically has small populations.

Short-term Trends

There have not been enough follow-up surveys to determine trends.

Long-term Trends

There have probably always been less than 50 populations in the state and there may have been some declines from loss of habitat but it is difficult to tell because of past misidentification of the species.

Conservation and Management


There are no immediate threats known for this species.

Conservation Strategies and Management Practices

No management needs are known at this time.

Research Needs

More research needs to be done into the best time of year to survey this plant in New York. Based on current data, we believe surveys should be conducted late summer and through the fall. All of the herbaria vouchers identified to either Carex lupuliformis or Carex lupulina should be verified to determine if they are indeed these species. Initial work has found that many specimens identified as Carex lupuliformis are actually large, healthy examples of Carex lupulina.



A sedge of silver maple-ash swamps, red maple hardwood swamps, floodplain forests, marshes, shrub swamps, and mucky soils. Often associated with limy clay or other types of calcareous soils (New York Natural Heritage Program 2004). Wet forests, especially in openings around forest ponds, riverine wetlands, marshes, wet thickets (Flora of North America 2002). In open marshes or along shores, sometimes in shallow water, or in very wet floodplain forests (Gleason & Cronquist 1991). Calcareous swamps, meadows and prairies (Fernald 1970).

Associated Ecological Communities

  • Deep emergent marsh* (guide)
  • Floodplain forest (guide)
  • Inland calcareous lake shore* (guide)
  • Red maple-hardwood swamp (guide)
  • Sedge meadow* (guide)
  • Shallow emergent marsh (guide)
  • Shrub swamp* (guide)
  • Silver maple-ash swamp (guide)
  • Unpaved road/path
  • Vernal pool* (guide)

Associated Species

  • Acer rubrum
  • Acer saccharinum (silver maple)
  • Apios americana (groundnut)
  • Bidens frondosa (devil's beggar-ticks)
  • Boehmeria cylindrica (false nettle)
  • Calamagrostis canadensis
  • Carex comosa (bristly sedge)
  • Carex crinita
  • Carex grayi (Gray's sedge)
  • Carex lupulina (hop sedge)
  • Carex tuckermanii (Tuckerman's sedge)
  • Cornus amomum
  • Eupatorium perfoliatum (boneset)
  • Fraxinus pennsylvanica (green ash)
  • Glyceria striata (fowl manna grass)
  • Leersia virginica (white cut grass)
  • Onoclea sensibilis (sensitive fern)
  • Symplocarpus foetidus (skunk-cabbage)


New York State Distribution

A bladder sedge with scattered populations throughout the state. Due to confusion with Carex lupulina, this plant may be reported from areas where it really is not present. The wetlands along Lake Champlain possibly possess some of the best populations of this plant in New York.

Global Distribution

A sedge ranging from Vermont and adjacent Quebec, west to Minnesota, south to Virginia, Kentucky, and Texas.

Best Places to See

  • Lachute River Delta

Identification Comments

General Description

This is a large stout sedge with one or a few erect stems up to 1.3 meters tall sticking out above the clump of wide green leaves. There are 1-5 large and fat cylinder-shaped female spikes toward the top of the stem with inflated flower bracts (perigynia). The diamond-shaped fruits have small knobs on the angles that often break through and stick out of the flower bracts late in the season.

Identifying Characteristics

A plant of wet soils, this bladder sedge (section Lupulinae) may have erect stems up to 1.3 meters tall. The key distinguishing feature of this plant is the presence of knobs or "nipple-like points" on the angles of mature achenes. As a useful field key, Carex lupuliformis tends to remain much greener late into the fall season compared to other sedges.

Best Life Stage for Proper Identification

Mature achenes are a must to properly identify this sedge.

Similar Species

More robust specimens of Carex lupulina are frequently confused for Carex lupuliformis. The achenes of Carex lupulina can have concave sides and the sharp angles are often confused for knobs. Comparison of the achenes of true Carex lupuliformis are advisable to determine exactly what is meant by the "achene knobs."

Best Time to See

While this sedge begins to flower in late spring and fruits begin to form by early July, mature fruits often do not form until late summer. These fruits will persist until early winter. The plants remain green until late fall. Since the plants stand out more after frost and have mature achenes at this point, the ideal survey time is late September to mid-November.

  • Fruiting

The time of year you would expect to find False Hop Sedge fruiting in New York.

False Hop Sedge Images

Images of Similar Species


False Hop Sedge
Carex lupuliformis Sartwell ex Dewey

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

Additional Common Names

  • Sedge

Comments on the Classification

This sedge is a member of the the easily recognized bladder sedge group (section Lupulinae).

Additional Resources

Best Identification Reference

Flora of North America Editorial Committee. 2002. Flora of North America, North of Mexico. Volume 23. Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford University Press, New York. 608 pp.

Other 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, New York State Department of Enviromental Conservation. March 1998. Element Occurrence Record Database. Latham, NY.

New York Natural Heritage Program. 2019. 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 University of South Florida]. New York Flora Association, Albany, New York


About This Guide

Information for this guide was last updated on: January 14, 2009

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Carex lupuliformis. Available from: Accessed March 25, 2019.

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