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Nabalus serpentaria; photograph Fritz Flohr Reynolds, CC BY-SA 2.0, via Wikimedia Commons CC BY-SAFritz Flohr Reynolds, CC BY-SA 2.0, via Wikimedia Commons

Nabalus serpentaria (Pursh) Hook.

Asteraceae · Connecticut, Massachusetts +18

English names not checked: Wikidata's common names were not read for this page.

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Nabalus serpentaria, photograph Fritzflohrreynolds, CC BY-SA 3.0, via Wikimedia CommonsNabalus serpentaria, photograph Fritz Flohr Reynolds, CC BY-SA 2.0, via Wikimedia CommonsNabalus serpentaria, photograph Judy Gallagher, CC BY 2.0, via Wikimedia Commons 4 photographs ›
Habitat figures
Cold floor (1 night in 100)
-12.0°C
Record low -25.7 °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)
1,190mm
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

Nabalus serpentarius (commonly known as cankerweed, gall-of-the-earth, or lion's-foot) is a perennial flower species found in North America.

Quoted from Wikipedia, "Nabalus serpentarius", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (841 mm of 1,186 mm) takes 8 months, March to September and December. Mean temperature moves 23.6 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: September to March and June.

Rain

1,186 mm in the median year at the habitat, 841 mm of it March to September and December. Wettest month July at 116 mm, driest month February at 79 mm. Across the grid cells of the range the year's total runs 1,107 mm to 1,442 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,190 mm, is the year's rain at the top of the page; the 1,186 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 11, the highest 90th-percentile month 41).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -12.0 °C, the absolute minimum -25.7 °C, 4,294 frost nights in 44 years, 97.6 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.2 °C. Monthly means: the coldest month's mean nightly low -1.7 °C in January (across the grid cells of the range -4.0 °C to 2.8 °C), the warmest month's mean daily high 29.5 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -12.0 °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: 55 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 -8 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 Nabalus serpentaria through the yearWarmest month July, mean daily high 30 °C; coldest month January, mean nightly low -1.7 °C; 1,186 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.-40°-20°0°20°40°frost37.2° 99th-percentile day, NASA POWER-25.7° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125150mm rainDLI 13–40RH 55–60%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 165 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 °C6 / 3–127 / 4–1412 / 8–1918 / 14–2323 / 19–2727 / 24–3030 / 27–3229 / 26–3125 / 22–2819 / 16–2313 / 11–188 / 6–13
Night °C-2 / -4–3-1 / -3–43 / 0–88 / 5–1213 / 11–1618 / 16–2121 / 19–2321 / 19–2317 / 15–2011 / 9–146 / 4–91 / -1–4
Rain mm88 / 78–12879 / 71–140106 / 96–141101 / 85–120102 / 93–121104 / 92–126116 / 100–141111 / 94–130101 / 90–11890 / 79–10788 / 80–120100 / 86–132
DLI15 / 13–1720 / 19–2227 / 26–2934 / 32–3738 / 37–4040 / 39–4139 / 38–4034 / 34–3629 / 27–3022 / 21–2515 / 14–1913 / 11–15
RH %57 / 56–5856 / 55–5855 / 54–5756 / 54–5758 / 56–5959 / 57–6159 / 57–6260 / 58–6359 / 58–6158 / 57–5957 / 56–5857 / 56–59
How this section is made
Each figure is the median across the 165 grid cells on land that hold in-range records (172 records in those cells; 1 more cell holds records but no land by the elevation layer, so those records sit at sea and the cell is left out), 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 1032:2047 (38.375, -77.625). Over 44 years there: absolute minimum -25.7 °C, 1st-percentile night -12.0 °C, 99th-percentile day 37.2 °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 165 distinct grid cells holding 172 of the 173 in-range records (1 further cell with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1032:2047 (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 38.50_-77.500, lapse-corrected -8 m at 6.5 °C/km. Elevation: ETOPO 2022, 79 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.

This species has no GBIF key of its own. Its records are GBIF's under the keys of the names Kew's World Checklist holds as this plant: 3090770 (Prenanthes serpentaria Pursh, 307 records), 4215453 (Nabalus albus var. serpentaria (Pursh) Torr., 0 records), 5705645 (Harpalyce serpentaria (Pursh) D.Don, 0 records), 7433007 (Prenanthes alba var. sepentaria (Pursh) Torr., 0 records). No name was matched to GBIF; the keys are read from Kew's synonymy. How.

NativeConnecticut, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, Rhode I., West Virginia, Alabama, Delaware, Florida, Georgia, Kentucky, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, District of Columbia · 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 marker39.395, -75.696 · in the densest population, 72 records (29% of those in range)
Evidence usedThe map marker rests on all 245 georeferenced records inside the native range; the climate across the range on the 172 of them in the land cells it reads, of 173 placed to within 10 km; the map shows only the 80 openly licensed ones, which alone would put the marker 244 km away. 3 records outside the WCVP native range not used. 72 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.
Other GBIF keysRecords also from GBIF's key 3090770 (Prenanthes serpentaria Pursh): Kew's file holds it as Prenanthes serpentaria Pursh (synonym under Nabalus serpentaria (Pursh) Hook.); 307 records, from GBIF's download.Records also from GBIF's key 4215453 (Nabalus albus var. serpentaria (Pursh) Torr.): Kew's file holds it as Nabalus albus var. serpentaria (Pursh) Torr. (synonym under Nabalus serpentaria (Pursh) Hook.); 0 records, from GBIF's search API on the day of the build.Records also from GBIF's key 5705645 (Harpalyce serpentaria (Pursh) D.Don): Kew's file holds it as Harpalyce serpentaria (Pursh) D.Don ex L.C.Beck (synonym under Nabalus serpentaria (Pursh) Hook.); 0 records, from GBIF's search API on the day of the build.Records also from GBIF's key 7433007 (Prenanthes alba var. sepentaria (Pursh) Torr.): Kew's file holds it as Prenanthes alba var. sepentaria (Pursh) Torr. (synonym under Nabalus serpentaria (Pursh) Hook.); 0 records, from GBIF's search API on the day of the build.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population of the 245 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Nabalus serpentaria, photograph 1did not loadNabalus serpentaria, photograph 2did not loadNabalus serpentaria, photograph 3did not load

Photographs: Fritzflohrreynolds, CC BY-SA 3.0, via Wikimedia Commons; Fritz Flohr Reynolds, CC BY-SA 2.0, via Wikimedia Commons; Judy Gallagher, CC BY 2.0, via Wikimedia Commons.

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

Smilax rotundifolia Smilax rotundifolia Common greenbrier Photo: CC0, author not statedAronia arbutifolia Aronia arbutifolia Red chokeberry Photo: CC0, author not statedArisaema pusillum Arisaema pusillum Small Jack-in-the-pulpit Photo: CC BY, Daniel McCloskyPeltandra virginica Peltandra virginica Tuckahoe Photo: CC0, author not statedDrosera filiformis Drosera filiformis Dew-thread Photo: CC BY, er-birdsSolidago gigantea Solidago gigantea Giant goldenrod Photo: CC0, author not stated

Other Nabalus 5 in the reference

Nabalus albus Nabalus albus White rattlesnake-root Photo: CC BY, RachelNabalus altissimus Nabalus altissimus Asteraceae Photo: CC0, Reuven MartinNabalus crepidineus Nabalus crepidineus Nodding rattlesnake-root Photo: CC BY, Chris StahlNabalus racemosus Nabalus racemosus Glaucous rattlesnake-root Photo: CC0, author not statedNabalus trifoliolatus Nabalus trifoliolatus Three-leaved rattlesnake-root Photo: CC BY-SA, Howard Williams

Names & registers

Also known as Nabalus serpentaria var. integrifolius; Prenanthes integrifolia; Prenanthes serpentaria f. simplicifolia; Prenanthes serpentaria; Nabalus serpentaria var. laevis and 11 more. (WCVP, RBG Kew)

IPNIPOWOWikidataWFOWikipedia

The record

Family
Asteraceae
Described by
(Pursh) Hook.
Native to
Connecticut, Massachusetts, New Jersey +17
Wild records
245 in range · 80 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 2026-10-22
Kew's names (WCVP) kew.names answeredas of 2026-06-04Kew's entry Nabalus serpentaria (Pursh) Hook. (plant_name_id 3061943), read from Kew's names file
GBIF species record gbif.species not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
GBIF synonyms gbif.synonyms not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
GBIF common names gbif.vernacular not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredasked 2026-10-22this species has no GBIF key of its own; its records are read under GBIF's keys for the names Kew's file holds as this plant, never by a name matched; GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 307 records of GBIF's key 3090770, Prenanthes serpentaria Pursh (Kew's file holds it as Prenanthes serpentaria Pursh (synonym under Nabalus serpentaria (Pursh) Hook.)): the GBIF download; 0 records of GBIF's key 4215453, Nabalus albus var. serpentaria (Pursh) Torr. (Kew's file holds it as Nabalus albus var. serpentaria (Pursh) Torr. (synonym under Nabalus serpentaria (Pursh) Hook.)): GBIF occurrence search API; 0 records of GBIF's key 5705645, Harpalyce serpentaria (Pursh) D.Don (Kew's file holds it as Harpalyce serpentaria (Pursh) D.Don ex L.C.Beck (synonym under Nabalus serpentaria (Pursh) Hook.)): GBIF occurrence search API; 0 records of GBIF's key 7433007, Prenanthes alba var. sepentaria (Pursh) Torr. (Kew's file holds it as Prenanthes alba var. sepentaria (Pursh) Torr. (synonym under Nabalus serpentaria (Pursh) Hook.)): GBIF occurrence search API; 7 records within 1 km of a botanic garden, herbarium or zoo left out (6 at a botanic garden or arboretum, 1 at a herbarium; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 38.50_-77.500, lapse-corrected -8 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by Kew's IPNI identifier 234078-1, POWO 234078-1
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild not asked
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
Wikimedia Commons commons answeredasked 2026-10-22
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 35 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…