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Heuchera richardsonii; photograph (c) Jeff Hansen, some rights reserved (CC BY) CC BY(c) Jeff Hansen, some rights reserved (CC BY) · observed growing wild · 2026-09-12

Heuchera richardsonii R.Br.

Richardson's alumroot; Prairie alumroot

Saxifragaceae · Northwest Territories, Alberta +19 · listed by its genus as a temperate garden plant

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Heuchera richardsonii, photograph author not stated, no rights reservedHeuchera richardsonii, photograph author not stated, no rights reservedHeuchera richardsonii, photograph (c) Mary Krieger, some rights reserved (CC BY)Heuchera richardsonii, photograph author not stated, no rights reservedHeuchera richardsonii, photograph author not stated, no rights reservedHeuchera richardsonii, photograph author not stated, no rights reserved 56 photographs ›
Habitat figures
Cold floor (1 night in 100)
-28.0°C
Record low -42.4 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
27°C
Jul at the habitat CHELSA
Rain a year (median across the range)
755mm
10 months of 25 mm or more in the median year CHELSA
Open-sky light
9–40DLI
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
Wet summers: the rain comes April to September, read as a summer growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

About the genus · Heuchera

Heuchera is a genus of largely evergreen perennial plants in the family Saxifragaceae. All species are native to North America except for Heuchera sichotensis, native to the Russian Far East. Common names include alumroot and coral bells.

Quoted from Wikipedia, "Heuchera", CC BY-SA 4.0.

Cultivation

Grouped as a temperate garden plant, listed under the genus Heuchera in the archetype table, and Kew describes it as “perennial”, “temperate”.

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (540 mm of 754 mm) falls in April to September, warmer than the year (wet-season mean 16.3 °C against a yearly mean of 6.9 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: October to March.

Rain

754 mm in the median year at the habitat, 540 mm of it April to September. Wettest month June at 111 mm, driest month February at 20 mm. Across the grid cells of the range the year's total runs 439 mm to 975 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 755 mm, is the year's rain at the top of the page; the 754 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: 9 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 6, the highest 90th-percentile month 43).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -28.0 °C, the absolute minimum -42.4 °C, 7,392 frost nights in 44 years, 168.0 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 30.6 °C. Monthly means: the coldest month's mean nightly low -13.1 °C in January (across the grid cells of the range -19.0 °C to -7.9 °C), the warmest month's mean daily high 27.0 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -28.0 °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: 54 to 64% 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 -73 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.

Group. Listed under the genus Heuchera in the archetype table, and Kew describes it as “perennial”, “temperate”. A group is taken only where Kew's description of the species agrees with the table's listing. The table gives no figure and no prose; the cold floor is the habitat's alone.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Heuchera richardsonii through the yearWarmest month July, mean daily high 27 °C; coldest month January, mean nightly low -13.1 °C; 754 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.-60°-40°-20°0°20°40°frost30.6° 99th-percentile day, NASA POWER-42.4° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125150mm rainDLI 9–40RH 54–64%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 952 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 °C-4 / -11–0-1 / -7–36 / 0–913 / 9–1520 / 15–2125 / 20–2627 / 23–2826 / 23–2821 / 17–2314 / 9–165 / 0–9-3 / -8–2
Night °C-13 / -19–-8-11 / -16–-7-5 / -9–-22 / -2–49 / 5–1114 / 10–1617 / 13–1917 / 12–1812 / 7–145 / 1–8-3 / -7–1-10 / -16–-6
Rain mm23 / 14–3820 / 12–4040 / 20–5968 / 28–9686 / 53–113111 / 76–12999 / 68–11691 / 53–12085 / 39–9862 / 25–8041 / 16–6728 / 14–50
DLI12 / 8–1418 / 15–2026 / 24–2733 / 32–3537 / 37–3940 / 38–4240 / 38–4335 / 33–3827 / 23–3018 / 14–2112 / 8–149 / 6–11
RH %64 / 59–7062 / 58–6858 / 56–6254 / 53–5555 / 53–5657 / 55–5858 / 55–5958 / 55–6058 / 54–5957 / 55–6060 / 58–6464 / 59–70
How this section is made
Each figure is the median across the 952 grid cells holding the 1431 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 902:1827 (44.875, -88.625). Over 44 years there: absolute minimum -42.4 °C, 1st-percentile night -28.0 °C, 99th-percentile day 30.6 °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 952 distinct grid cells holding 1431 of the 1431 in-range records; extremes and elevation at the typical cell 902:1827 (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 45.00_-88.750, lapse-corrected -73 m at 6.5 °C/km. Elevation: ETOPO 2022, 269 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.
NativeNorthwest Territories, Alberta, British Columbia, Manitoba, Saskatchewan, Ontario, Colorado, Montana, Wyoming, Illinois, Iowa, Kansas, Minnesota, Missouri, North Dakota, Nebraska, Oklahoma, South Dakota, Wisconsin, Indiana, Michigan · 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 marker43.415, -89.723 · in the densest population, 623 records (36% of those in range)
Kew's description“perennial” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1743 georeferenced records inside the native range; the climate across the range on the 1431 of them placed to within 10 km; the map shows only the 643 openly licensed ones, which alone would put the marker 309 km away. 1 record outside the WCVP native range not used. 312 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 2° block of the 1743 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Heuchera richardsonii, photograph 1did not loadHeuchera richardsonii, photograph 2did not loadHeuchera richardsonii, photograph 3did not loadHeuchera richardsonii, photograph 4did not loadHeuchera richardsonii, photograph 5did not loadHeuchera richardsonii, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0 (5); (c) Mary Krieger, some rights reserved (CC BY).

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

Ranunculus rhomboideus Ranunculus rhomboideus Prairie buttercup Photo: CC BY, treelogicalDrymocallis arguta Drymocallis arguta Tall cinquefoil Photo: CC0, author not statedHumulus americanus Humulus americanus American hops Photo: CC0, author not statedBetula × sandbergii Betula × sandbergii Sandberg's birch Photo: CC0, author not statedAnemone cylindrica Anemone cylindrica Candle anemone Photo: CC0, author not statedAllium stellatum Allium stellatum Autumn onion Photo: CC0, author not stated

Other Heuchera 26 in the reference

Heuchera alba Heuchera alba White alumroot Photo: CC BY, Daniel BeeversHeuchera americana Heuchera americana American alumroot Photo: CC BY, John MichaelHeuchera bracteata Heuchera bracteata Rocky Mountain alumroot Photo: CC0, author not statedHeuchera caroliniana Heuchera caroliniana Carolina alumroot Photo: CC BY, Alison NorthupHeuchera chlorantha Heuchera chlorantha Meadow alumroot Photo: CC BY, jonsenseHeuchera cylindrica Heuchera cylindrica Mat alumroot Photo: CC BY, Daughter DadHeuchera elegans Heuchera elegans Urn-flowered Alumroot Photo: CC0, author not statedHeuchera glabra Heuchera glabra Alpine alumroot Photo: CC BY, Shaan AroesteHeuchera grossulariifolia Heuchera grossulariifolia Gooseberry-leaf alumroot Photo: CC BY, Kieran HanrahanHeuchera hallii Heuchera hallii Front Range alumroot Photo: CC BY-SA, Brian FinzelHeuchera longiflora Heuchera longiflora Long-flowered alum-root Photo: CC BY, Shelby Lyn SandersHeuchera longipetala Heuchera longipetala Saxifragaceae Photo: CC BY-SA, Leticia Jiménez Hernández all 27 ›

Names & registers

Also known as Heuchera hispida var. richardsonii; Heuchera richardsonii var. affinis; Heuchera richardsonii var. grayana; Heuchera richardsonii var. hispidior; Heuchera richardsonii var. richardsonii and 1 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataiNaturalist

The record

Family
Saxifragaceae
Described by
R.Br.
Native to
Northwest Territories, Alberta, British Columbia +18
Wild records
1743 in range · 643 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
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
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; 41 records within 1 km of a botanic garden, herbarium or zoo left out (34 at a botanic garden or arboretum, 1 at a herbarium, 6 at a zoo; 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 45.00_-88.750, lapse-corrected -73 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia nothing to reportasked 2026-10-22
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 2026-10-22
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 55 datasets via GBIF.org; each carries its own licence.

Cultifolio

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