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Aralia californica; photograph (c) Lia Keener, some rights reserved (CC BY) CC BY(c) Lia Keener, some rights reserved (CC BY) · observed growing wild · 2026-09-26

Aralia californica S.Watson

California spikenard; California-ginseng; Elk-clover; Western-spikenard

Araliaceae · Oregon, California

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Aralia californica, photograph (c) er-birds, some rights reserved (CC BY)Aralia californica, photograph (c) er-birds, some rights reserved (CC BY)Aralia californica, photograph (c) er-birds, some rights reserved (CC BY)Aralia californica, photograph (c) er-birds, some rights reserved (CC BY)Aralia californica, photograph (c) er-birds, some rights reserved (CC BY)Aralia californica, photograph (c) Arvel Hernandez, some rights reserved (CC BY) 84 photographs ›
Habitat figures
Cold floor (1 night in 100)
-2.7°C
Record low -9.8 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
27°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
1,400mm
8 months of 25 mm or more in the median year CHELSA
Open-sky light
12–51DLI
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, read as a winter growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Aralia californica, known by the common name elk clover, California aralia and California spikenard is a large deciduous perennial herb native to California and Oregon in the family Araliaceae. It occurs primarily in moist, shaded habitats such as streambanks, canyons and mixed forests. The plant can reach 2-3 m in height and produces very large compound leaves. It has small, greenish-white flowers that occur in branched clusters, followed by dark purple to black fruits.

Quoted from Wikipedia, "Aralia californica", CC BY-SA 4.0.

About the genus · Aralia

Aralia, or spikenard, is a genus of the family Araliaceae, consisting of 68 accepted species of deciduous or evergreen trees, shrubs, and rhizomatous herbaceous perennials. The genus is native to Asia and the Americas, with most species occurring in mountain woodlands. Aralia plants vary in size, with some herbaceous species only reaching 50 centimetres (20 in) tall, while some are trees growing to 20 metres (66 ft) tall.

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

Cultivation

Seasons

The rain rule reads a winter growing season: 70% of the median year's rain (1,089 mm of 1,379 mm) falls in November to March, cooler than the year (wet-season mean 6.9 °C against a yearly mean of 11.8 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: May to September.

Rain

1,379 mm in the median year at the habitat, 1,089 mm of it November to March. Wettest month December at 277 mm, driest month July at 3 mm; 1 month under 5 mm. Across the grid cells of the range the year's total runs 784 mm to 2,196 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,400 mm, is the year's rain at the top of the page; the 1,379 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: 12 to 51 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 53).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -2.7 °C, the absolute minimum -9.8 °C, 1,127 frost nights in 44 years, 25.6 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 39.8 °C. Monthly means: the coldest month's mean nightly low 1.7 °C in January (across the grid cells of the range -1.8 °C to 7.0 °C), the warmest month's mean daily high 26.8 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: -2.7 °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 62% 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 -252 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 Aralia californica through the yearWarmest months July and August, mean daily high 27 °C; coldest month January, mean nightly low 1.7 °C; 1,379 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.-20°-10°0°10°20°30°40°50°frost39.8° 99th-percentile day, NASA POWER-9.8° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 12–51RH 54–62%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 439 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 °C10 / 6–1311 / 8–1413 / 10–1615 / 13–1819 / 16–2223 / 18–2727 / 20–3127 / 20–3124 / 20–2819 / 17–2313 / 10–1610 / 6–13
Night °C2 / -2–72 / -2–73 / 0–85 / 1–98 / 5–1011 / 8–1313 / 11–1513 / 11–1512 / 9–149 / 5–125 / 1–92 / -2–7
Rain mm238 / 150–369202 / 140–315175 / 110–28997 / 50–17158 / 19–12223 / 4–743 / 1–197 / 2–2220 / 7–5682 / 39–163197 / 96–328277 / 144–433
DLI13 / 10–1719 / 16–2328 / 24–3238 / 32–4145 / 39–4750 / 44–5251 / 48–5345 / 43–4837 / 33–3926 / 21–2915 / 11–2012 / 9–15
RH %62 / 56–6562 / 58–6461 / 57–6460 / 54–6359 / 51–6457 / 47–6354 / 43–6454 / 43–6454 / 45–6157 / 49–6161 / 54–6561 / 56–65
How this section is made
Each figure is the median across the 439 grid cells on land that hold in-range records (1176 records in those cells; 2 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are 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 1011:1135 (39.425, -123.225). Over 44 years there: absolute minimum -9.8 °C, 1st-percentile night -2.7 °C, 99th-percentile day 39.8 °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 439 distinct grid cells holding 1176 of the 1178 in-range records (2 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1011:1135 (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_-123.125, lapse-corrected -252 m at 6.5 °C/km. Elevation: ETOPO 2022, 598 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.
NativeOregon, California · introduced: Germany · 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 marker37.916, -122.583 · in the densest population, 766 records (59% 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 1292 georeferenced records inside the native range; the climate across the range on the 1176 of them in the land cells it reads, of 1178 placed to within 10 km; the map shows only the 224 openly licensed ones, which alone would put the marker 2 km away. 4 records outside the WCVP native range not used. 114 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 1292 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Aralia californica, photograph 1did not loadAralia californica, photograph 2did not loadAralia californica, photograph 3did not loadAralia californica, photograph 4did not loadAralia californica, photograph 5did not loadAralia californica, photograph 6did not load

Photographs: (c) er-birds, some rights reserved (CC BY) (5); (c) Arvel Hernandez, some rights reserved (CC BY).

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

Euonymus occidentalis Euonymus occidentalis Western burning-bush Photo: CC BY, Jacobb L. Foster IIDichelostemma ida-maia Dichelostemma ida-maia Firecracker flower Photo: CC0, author not statedCalochortus tolmiei Calochortus tolmiei Tolmie star-tulip Photo: CC BY, Alexander WentworthRupertia physodes Rupertia physodes Forest scurf-pea Photo: CC0, author not statedCarex nudata Carex nudata Naked sedge Photo: CC BY, Elly PoretskyDichelostemma congestum Dichelostemma congestum Ookow Photo: CC BY, Parker James Lloyd

Other Aralia 13 in the reference

Aralia bipinnata Aralia bipinnata Araliaceae Photo: CC0, author not statedAralia cachemirica Aralia cachemirica Araliaceae Photo: CC BY, Morten RossAralia chinensis Aralia chinensis Chinese angelica-tree Photo: CC0, author not statedAralia continentalis Aralia continentalis Manchurian-spikenard Photo: CC BY, Tatyana PetrenkoAralia cordata Aralia cordata Japanese-spikenard Photo: CC BY, mami_t_tAralia decaisneana Aralia decaisneana Decaisne's spikenard Photo: CC BY, 呂一起(Lyu yi-chi)Aralia echinocaulis Aralia echinocaulis Araliaceae Photo: CC BY-SA, peganum from Henfield, EnglandAralia elata Aralia elata Japanese angelica tree Photo: CC BY, the swamp assAralia hispida Aralia hispida Bristly sarsaparilla Photo: CC BY, Steven LamondeAralia nudicaulis Aralia nudicaulis Wild sarsaparilla Photo: CC BY, Andrew LaiAralia racemosa Aralia racemosa American-spikenard Photo: CC0, author not statedAralia spinosa Aralia spinosa Devil's walking-stick Photo: CC0, author not stated all 14 ›

Names & registers

Also known as Aralia californica var. acuminata; Aralia racemosa var. occidentalis. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Araliaceae
Described by
S.Watson
Native to
Oregon, California
Wild records
1292 in range · 224 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; 63 records within 1 km of a botanic garden, herbarium or zoo left out (60 at a botanic garden or arboretum, 3 at a herbarium; 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_-123.125, lapse-corrected -252 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 43 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…