Carex billingsii(O.W.Knight) Kirschb.

Billings' Sedge

WFO wfo-0000835284 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Carex billingsii, photographed by Reuven Martin
fig. a Reuven Martin, CC0 1.0 / 2021-07-04 / obs. 140999779
Carex billingsii, photographed by Quinten Wiegersma
fig. b Quinten Wiegersma, CC BY 4.0 / obs. 135409040
Carex billingsii, photographed by Quinten Wiegersma
fig. c Quinten Wiegersma, CC BY 4.0 / obs. 83370388
Carex billingsii, photographed by Douglas Goldman
fig. d Douglas Goldman, CC BY-SA 4.0 / obs. 49884379
Carex billingsii, photographed by Henrique Pacheco
fig. e Henrique Pacheco, CC BY 4.0 / obs. 146151643
Carex billingsii, photographed by Étienne Lacroix-Carignan
fig. f Étienne Lacroix-Carignan, CC0 1.0 / obs. 88129191
Carex billingsii, photographed by Chris Hoess
fig. g Chris Hoess, CC BY-SA 4.0 / obs. 43589665
Carex billingsii, photographed by naturalist charlie
fig. h naturalist charlie, CC BY 4.0 / obs. 4874205

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
2309221
Filed as
Carex billingsii (O.W.Knight) Kirschb.
Det. by
not recorded on this sheet
Collected
W. A. Matthews 1922-07-17
Origin
US
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 16 botanical countries

Regions where Carex billingsii is native: Connecticut, Maine, Massachusetts, Michigan, New Brunswick, New Hampshire, New Jersey, New York, Newfoundland, Nova Scotia, Ontario, Pennsylvania, Prince Edward I., Québec, Rhode I., Vermont ConnecticutMaineMassachusettsMichiganNew BrunswickNew HampshireNew JerseyNew YorkNewfoundlandNova ScotiaOntarioPennsylvaniaPrince Edward I.QuébecVermont Rhode I.
Native distribution of Carex billingsii, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Connecticut CNT NORTHERN AMERICA
Maine MAI
Massachusetts MAS
Michigan MIC
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New York NWY
Newfoundland NFL
Nova Scotia NSC
Ontario ONT
Pennsylvania PEN
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
Vermont VER

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 156 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -16.4 °C -12.7 °C -4.0 °C
Warmest month, mean daily high 19.8 °C 24.1 °C 26.3 °C
Annual rainfall 835 mm 1,078 mm 1,459 mm
Rainfall in the driest quarter 137 mm 217 mm 317 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 156 research-grade observations of Carex billingsii that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 2 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Carex trisperma f. billingsii (O.W.Knight) B.Boivin
  • Carex trisperma var. billingsii O.W.Knight

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. USDA PLANTS Database. common name, checklist symbol CABI22. public domain. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.