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Carex lupuliformis; photograph (c) Anne Parker, some rights reserved (CC BY) CC BY(c) Anne Parker, some rights reserved (CC BY) · observed growing wild · 2026-08-29

Carex lupuliformis Sartwell ex Dewey

False hop sedge; Hop-like sedge; Knobbed hop sedge; Knotted hop sedge

Cyperaceae · Ontario, Québec +30

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Carex lupuliformis, photograph (c) Anne Parker, some rights reserved (CC BY)Carex lupuliformis, photograph (c) Anne Parker, some rights reserved (CC BY)Carex lupuliformis, photograph (c) Anne Parker, some rights reserved (CC BY)Carex lupuliformis, photograph (c) Anne Parker, some rights reserved (CC BY)Carex lupuliformis, photograph (c) Anne Parker, some rights reserved (CC BY)Carex lupuliformis, photograph (c) Anne Parker, some rights reserved (CC BY) 146 photographs ›
Habitat figures
Cold floor (1 night in 100)
-12.2°C
Record low -24.2 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
30°C
Jul at the habitat CHELSA
Rain a year (median across the range)
1,245mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
13–40DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Rain spread: 70% of the median year's rain takes 8 months, so no short rainy season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Carex lupuliformis, common name false hop sedge, is a perennial sedge of sporadic distribution found in the floodplain forests and ephemeral woodland ponds of central and eastern North America. The species typically produces four to seven leaves with sheaths of distal leaves of 3 to 21 cm whose ligules are rounded to triangular. Carex lupuliformis blooms between early June and early October, typically with "two to six proximal female spikes, distal spikes usually crowded, ascending, densely flowered, usually cylindric, much longer than broad; one to two terminal male spikes." Fruiting occurs between late July through early October. More on Wikipedia ›

Quoted from Wikipedia, "Carex lupuliformis", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (842 mm of 1,191 mm) takes 8 months, March to October. Mean temperature moves 24.8 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: September to April.

Rain

1,191 mm in the median year at the habitat, 842 mm of it March to October. Wettest months (2 at 112 mm), driest month February at 78 mm. Across the grid cells of the range the year's total runs 988 mm to 1,435 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,245 mm, is the year's rain at the top of the page; the 1,191 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 13 to 40 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA; the lowest 10th-percentile month across the cells is 9, the highest 90th-percentile month 42).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -12.2 °C, the absolute minimum -24.2 °C, 4,231 frost nights in 44 years, 96.2 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 35.0 °C. Monthly means: the coldest month's mean nightly low -2.9 °C in January (across the grid cells of the range -9.7 °C to 9.8 °C), the warmest month's mean daily high 30.3 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -12.2 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 56 to 60% across the year (monthly means, median year across the grid cells of the range, CHELSA). A figure about the air, saying nothing about how the plant takes water.

How this section is made

Each card states this species' habitat figures with their sources, and what two fixed rules read from them; nothing here says what the plant does, wants or tolerates. The rules · the terms.

Seasons. Read from the median year of CHELSA monthly rainfall and mean temperature across the grid cells of the range: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve moves 4 °C or more and the habitat lies 10° or more from the equator. A reading of the curves, not an observation of the plant.

Rain. CHELSA monthly precipitation, median year across the grid cells of the range. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light. CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Temperature. NASA POWER daily minima and maxima over 44 years at a typical spot in the range, lapse-corrected -3 m to its elevation; CHELSA monthly means, median year across the grid cells of the range. The cold floor is the 1st-percentile night named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity. CHELSA relative humidity, median year across the grid cells of the range.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Carex lupuliformis through the yearWarmest month July, mean daily high 30 °C; coldest month January, mean nightly low -2.9 °C; 1,191 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, northern hemisphere.-30°-20°-10°0°10°20°30°40°frost35.0° 99th-percentile day, NASA POWER-24.2° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200mm rainDLI 13–40RH 56–60%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 183 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C5 / -2–188 / 0–2013 / 5–2219 / 12–2624 / 19–2928 / 24–3230 / 26–3329 / 25–3326 / 21–3020 / 14–2713 / 8–237 / 1–19
Night °C-3 / -10–10-1 / -9–113 / -4–139 / 3–1614 / 9–2019 / 14–2321 / 17–2421 / 17–2417 / 13–2311 / 7–195 / 1–15-1 / -6–11
Rain mm83 / 49–11678 / 49–118100 / 62–12899 / 71–127110 / 83–144112 / 92–182112 / 93–188106 / 73–200102 / 83–163101 / 74–12897 / 59–12791 / 55–138
DLI15 / 11–2120 / 17–2527 / 25–3234 / 32–3938 / 36–4140 / 38–4239 / 38–4235 / 33–3829 / 26–3222 / 18–2715 / 11–2213 / 9–19
RH %58 / 57–6258 / 56–6156 / 55–5856 / 55–5858 / 56–5959 / 57–6259 / 57–6360 / 57–6459 / 56–6358 / 56–6059 / 57–6159 / 57–62
How this section is made
Each figure is the median across the 183 grid cells holding the 229 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 1006:2085 (39.675, -75.725). Over 44 years there: absolute minimum -24.2 °C, 1st-percentile night -12.2 °C, 99th-percentile day 35.0 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 183 distinct grid cells holding 229 of the 229 in-range records; extremes and elevation at the typical cell 1006:2085 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 39.50_-75.625, lapse-corrected -3 m at 6.5 °C/km. Elevation: ETOPO 2022, 26 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeOntario, Québec, Illinois, Iowa, Minnesota, Missouri, Oklahoma, Wisconsin, Connecticut, Indiana, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, Vermont, West Virginia, Texas, Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker29.426, -82.115 · in the densest population, 226 records (38% of those in range)
Kew's description“perennial or rhizomatous geophyte” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 592 georeferenced records inside the native range; the climate across the range on the 229 of them placed to within 10 km; the map shows only the 368 openly licensed ones, which alone would put the marker 36 km away. 363 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 592 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Carex lupuliformis, photograph 1did not loadCarex lupuliformis, photograph 2did not loadCarex lupuliformis, photograph 3did not loadCarex lupuliformis, photograph 4did not loadCarex lupuliformis, photograph 5did not loadCarex lupuliformis, photograph 6did not load

Photographs: (c) Anne Parker, some rights reserved (CC BY) (6).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Pycnanthemum tenuifolium Pycnanthemum tenuifolium Narrow-leaf mountain-mint Photo: CC0, author not statedBidens polylepis Bidens polylepis Ozark beggarticks Photo: CC BY-SA, Judy GallagherCarex glaucodea Carex glaucodea Blue sedge Photo: CC BY, Zac PetersonMimulus alatus Mimulus alatus Sharp-wing monkey-flower Photo: CC BY, hr_dragonflyBidens bipinnata Bidens bipinnata Spanish needles Photo: CC0, author not statedCuscuta pentagona Cuscuta pentagona Five-angled dodder Photo: CC0, author not stated

Other Carex 301 in the reference

Carex acuta Carex acuta Slender Tufted-sedge Photo: CC BY, Михаил ЯзыковCarex acutiformis Carex acutiformis Lesser pond-sedge Photo: CC BY, Sascha NunheimCarex adelostoma Carex adelostoma Circumpolar sedge Photo: CC0, author not statedCarex alba Carex alba Cyperaceae Photo: CC0, author not statedCarex albicans Carex albicans White-tinged sedge Photo: CC BY, Ryan SorrellsCarex albula Carex albula Blonde Sedge Photo: CC BY, John BarklaCarex albursina Carex albursina White bear sedge Photo: CC BY, sofi vCarex alopecoidea Carex alopecoidea Foxtail sedge Photo: CC0, author not statedCarex amphibola Carex amphibola Amphibious sedge Photo: CC BY, Nathan AaronCarex amplifolia Carex amplifolia Big-leaved sedge Photo: CC0, author not statedCarex annectens Carex annectens Yellow-fruited sedge Photo: CC0, author not statedCarex appalachica Carex appalachica Appalachian sedge Photo: CC BY, Jaime McGuigan all 302 ›

Names & registers

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Cyperaceae
Described by
Sartwell ex Dewey
Native to
Ontario, Québec, Illinois +29
Wild records
592 in range · 368 open

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-21
GBIF species record gbif.species answeredasked 2026-10-21
GBIF synonyms gbif.synonyms answeredasked 2026-10-21
GBIF common names gbif.vernacular answeredasked 2026-10-21names fetched 2026-10-21
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 5 records within 1 km of a botanic garden, herbarium or zoo left out (3 at a botanic garden or arboretum, 1 at a herbarium, 1 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-21
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-21NASA POWER (MERRA-2) daily 1981–2024, cell 39.50_-75.625, lapse-corrected -3 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-21
Wikipedia wikipedia answeredasked 2026-10-21
iNaturalist photographs, wild inat.photos.wild answeredasked 2026-10-22from iNaturalist's open data of 2026-09-27: research-grade observations with an open-licence photograph, the 24 whose photographs iNaturalist received last (the open data holds no votes); filled 2026-10-22
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-21
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 71 datasets via GBIF.org; each carries its own licence.

Cultifolio

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