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Heuchera parishii; photograph (c) Trevor Van Loon, some rights reserved (CC BY) CC BY(c) Trevor Van Loon, some rights reserved (CC BY) · observed growing wild · 2026-07-18

Heuchera parishii Rydb.

Mill Creek alumroot; Parish's alumroot

Saxifragaceae · California · listed by its genus as a temperate garden plant

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Heuchera parishii, photograph (c) Trevor Van Loon, some rights reserved (CC BY)Heuchera parishii, photograph (c) Trevor Van Loon, some rights reserved (CC BY)Heuchera parishii, photograph (c) Trevor Van Loon, some rights reserved (CC BY)Heuchera parishii, photograph (c) Trevor Van Loon, some rights reserved (CC BY)Heuchera parishii, photograph (c) Trevor Van Loon, some rights reserved (CC BY)Heuchera parishii, photograph author not stated, no rights reserved 9 photographs ›
Habitat figures
Coldest month, mean nightly low
-3.7°C
Jan and Dec at the habitat, not a floor; extremes not used (the weather cell's ground is too far off) CHELSA
Warmest month, mean daily high
26°C
Jul at the habitat CHELSA
Rain a year (median across the range)
560mm
7 months of 25 mm or more in the median year CHELSA
Open-sky light
20–55DLI
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 winters: the rain comes November to March, with nights below freezing; no growing season read. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Heuchera parishii is a species of flowering plant in the saxifrage family known by the common names Mill Creek alumroot and Parish's alumroot. It is endemic to California, where it is found in the San Bernardino Mountains. This is a rhizomatous perennial herb producing a patch of lobed, kidney-shaped leaves up to four centimeters wide. It bears an erect inflorescence up to about 27 centimeters in height which blooms in dense clusters of salmon-pink flowers. More on Wikipedia ›

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

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 rainy season and no growing season: 70% of the median year's rain (433 mm of 564 mm) falls in November to March, the cooler part of the year, but the mean nightly low is below freezing in February, March, April, December and January, so the rule reads no growing season from it. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: May to September.

Rain

564 mm in the median year at the habitat, 433 mm of it November to March. Wettest month February at 113 mm, driest month June at 5 mm. Across the grid cells of the range the year's total runs 366 mm to 845 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 560 mm, is the year's rain at the top of the page; the 564 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: 20 to 55 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 16, the highest 90th-percentile month 56).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low -3.7 °C in January and December (across the grid cells of the range -6.5 °C to 0.8 °C), the warmest month's mean daily high 26.1 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is -3.7 °C, the coldest month's mean nightly low, January and December, in the median year (CHELSA); a month's mean of its nightly lows is warmer than the nights a floor is read from. The daily extremes were read at a weather cell whose ground is too far above or below the typical spot to correct for, and are not used.

Humidity

Relative humidity at the habitat: 38 to 47% 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. CHELSA monthly means, median year across the grid cells of the range. No cold floor is read without a daily extremes series; the coldest month's mean nightly low named in its sentence is not one. 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 parishii through the yearWarmest month July, mean daily high 26 °C; coldest months January and December, mean nightly low -3.7 °C; 564 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, northern hemisphere.-10°0°10°20°30°40°frost°C · day and nightcold quarter050100150200mm rainDLI 20–55RH 38–47%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 29 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C7 / 4–117 / 5–1210 / 8–1514 / 11–1819 / 16–2323 / 21–2826 / 23–3025 / 23–3022 / 20–2717 / 14–2111 / 8–156 / 4–11
Night °C-4 / -7–1-3 / -6–1-2 / -4–30 / -2–55 / 2–99 / 6–1312 / 10–1712 / 10–179 / 7–135 / 2–90 / -3–4-4 / -7–1
Rain mm107 / 65–162113 / 67–17981 / 50–13040 / 19–6912 / 9–195 / 4–614 / 11–1820 / 15–2314 / 13–1626 / 19–4046 / 31–7386 / 57–124
DLI21 / 18–2426 / 24–2936 / 35–3946 / 44–4851 / 51–5355 / 54–5651 / 50–5247 / 45–4841 / 39–4332 / 29–3524 / 21–2620 / 16–22
RH %45 / 44–4947 / 46–5147 / 45–5044 / 42–4942 / 40–4738 / 37–4340 / 39–4342 / 41–4442 / 41–4442 / 41–4543 / 41–4744 / 42–48

The daily extremes were not used: the correction for elevation, +1211 m, is beyond the 1,000 m either way that a lapse rate is applied over, so the weather cell's ground is other terrain than the typical spot's. So no cold floor is read for this species, and the coldest month's mean nightly low is not taken as one. What that cell gave, so corrected, over 44 years: absolute minimum -16.8 °C, 1st-percentile night -10.8 °C.

How this section is made
Each figure is the median across the 29 grid cells holding the 88 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 1115:1260 (34.225, -116.975). 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 29 distinct grid cells holding 88 of the 88 in-range records; extremes and elevation at the typical cell 1115:1260 (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 34.00_-116.875, lapse-corrected +1211 m at 6.5 °C/km. Elevation: ETOPO 2022, 2194 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.
NativeCalifornia · 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 marker34.122, -116.853 · in the densest population, 138 records (99% 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 139 georeferenced records inside the native range; the climate across the range on the 88 of them placed to within 10 km; the map shows only the 9 openly licensed ones, which alone would put the marker 2 km away. 51 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 of the 139 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 parishii, photograph 1did not loadHeuchera parishii, photograph 2did not loadHeuchera parishii, photograph 3did not loadHeuchera parishii, photograph 4did not loadHeuchera parishii, photograph 5did not loadHeuchera parishii, photograph 6did not load

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

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

Silene parishii Silene parishii Parish's catchfly Photo: CC0, author not statedLilium parryi Lilium parryi Lemon lily Photo: CC BY, Trevor Van LoonFritillaria pinetorum Fritillaria pinetorum Pinewoods fritillary Photo: CC BY, James M. MaleyEriogonum kennedyi Eriogonum kennedyi Kennedy's buckwheat Photo: CC BY, Steve MatsonMonardella linoides Monardella linoides Flaxleaf monardella Photo: CC0, author not statedThalictrum fendleri Thalictrum fendleri Fendler's meadow-rue Photo: CC BY, Daughter Dad

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 parishii f. tubiformis; Heuchera rubescens var. parishii. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Saxifragaceae
Described by
Rydb.
Native to
California
Wild records
139 in range · 9 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
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 34.00_-116.875, lapse-corrected +1211 m at 6.5 °C/km; read, and set aside: the correction for elevation, +1211 m, is beyond the 1,000 m either way that a lapse rate is applied over, so the weather cell's ground is other terrain than the typical spot's, so no cold floor is shown
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia answeredasked 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 2026-10-22none of the photographs on this page is credited to GBIF: those shown are other sources', and GBIF's were the same photographs or were set aside by the photograph rules
Wikimedia Commons commons nothing to reportasked 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 10 datasets via GBIF.org; each carries its own licence.

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