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An example collection, so you can see what this page does. Nothing added here is kept: leaving deletes it.
Cornus torreyi; photograph Elliott Gordon, CC BY, iNaturalist via GBIF CC BYElliott Gordon, CC BY, iNaturalist via GBIF

Cornus torreyi S.Watson

Cornaceae · Alaska, British Columbia +7

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Cornus torreyi, photograph Elliott Gordon, CC BY, iNaturalist via GBIFCornus torreyi, photograph sblumen, CC BY, iNaturalist via GBIFCornus torreyi, photograph sblumen, CC BY, iNaturalist via GBIFCornus torreyi, photograph sblumen, CC BY, iNaturalist via GBIFCornus torreyi, photograph Senna Bryce Robeson, CC BY, iNaturalist via GBIFCornus torreyi, photograph Sam Beaumont, CC BY, iNaturalist via GBIF 24 photographs ›
Habitat figures
Cold floor (1 night in 100)
-11.2°C
Record low -20.0 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
26°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
939mm
10 months of 25 mm or more in the median year CHELSA
Open-sky light
8–48DLI
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 October 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

Cornus torreyi, the western dogwood or creek dogwood, is a species of flowering plant in the family Cornaceae. It is native to the west coast of North America, from Alaska down to northern Baja California, and inland to Idaho and Montana. A deciduous shrub usually 1 to 6 m (3 to 20 ft) tall, its slender branches turn purplish-red in the sun but remain green in the shade.

Quoted from Wikipedia, "Cornus torreyi", CC BY-SA 4.0.

About the genus · Cornus

Cornus is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods or cornels, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrubs, but a few species are nearly herbaceous perennial subshrubs, and some species are evergreen. Several species have small heads of inconspicuous flowers surrounded by an involucre of large, typically white petal-like bracts, while others have more open clusters of petal-bearing flowers. More on Wikipedia ›

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

Cultivation

Seasons

The rain rule reads a winter growing season: 70% of the median year's rain (719 mm of 931 mm) falls in October to March, cooler than the year (wet-season mean 6.2 °C against a yearly mean of 10.6 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to September.

Rain

931 mm in the median year at the habitat, 719 mm of it October to March. Wettest month January at 147 mm, driest month July at 15 mm. Across the grid cells of the range the year's total runs 467 mm to 1,886 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 939 mm, is the year's rain at the top of the page; the 931 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: 8 to 48 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 53).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -11.2 °C, the absolute minimum -20.0 °C, 2,261 frost nights in 44 years, 51.4 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 30.8 °C. Monthly means: the coldest month's mean nightly low 0.4 °C in December (across the grid cells of the range -7.5 °C to 6.8 °C), the warmest month's mean daily high 26.0 °C in July and August (median year across the grid cells of the range, CHELSA). Cold floor: -11.2 °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: 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 -489 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 Cornus torreyi through the yearWarmest months July and August, mean daily high 26 °C; coldest month December, mean nightly low 0.4 °C; 931 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°frost30.8° 99th-percentile day, NASA POWER-20.0° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400mm rainDLI 8–48RH 54–64%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 373 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 °C7 / 0–148 / 2–1511 / 6–1614 / 9–1918 / 14–2222 / 17–2726 / 19–3026 / 20–3022 / 18–2716 / 12–2210 / 4–177 / -1–14
Night °C1 / -7–71 / -6–72 / -4–85 / -1–98 / 3–1111 / 7–1313 / 10–1613 / 10–1611 / 7–147 / 2–123 / -4–90 / -8–7
Rain mm147 / 64–282121 / 51–231108 / 50–21563 / 33–13953 / 12–10635 / 4–9315 / 1–4617 / 2–4429 / 6–7568 / 26–166130 / 48–289145 / 60–313
DLI10 / 7–2017 / 12–2525 / 20–3535 / 28–4442 / 35–5045 / 37–5348 / 40–5343 / 35–4832 / 26–4020 / 15–3111 / 7–228 / 6–18
RH %64 / 53–6862 / 55–6560 / 55–6458 / 52–6357 / 49–6356 / 45–6354 / 42–6254 / 43–6355 / 45–6358 / 48–6563 / 51–6863 / 53–68
How this section is made
Each figure is the median across the 373 grid cells on land that hold in-range records (441 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 805:1137 (49.725, -123.125). Over 44 years there: absolute minimum -20.0 °C, 1st-percentile night -11.2 °C, 99th-percentile day 30.8 °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 373 distinct grid cells holding 441 of the 443 in-range records (2 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 805:1137 (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 49.50_-123.125, lapse-corrected -489 m at 6.5 °C/km. Elevation: ETOPO 2022, 76 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.
NativeAlaska, British Columbia, Idaho, Montana, Oregon, Washington, California, Nevada, Mexico Northwest · 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 marker45.594, -122.781 · in the densest population, 360 records (58% of those in range)
Kew's description“shrub” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 618 georeferenced records inside the native range; the climate across the range on the 441 of them in the land cells it reads, of 443 placed to within 10 km; the map shows only the 248 openly licensed ones, which alone would put the marker 343 km away. 11 records outside the WCVP native range not used. 175 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 618 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Cornus torreyi, photograph 1did not loadCornus torreyi, photograph 2did not loadCornus torreyi, photograph 3did not loadCornus torreyi, photograph 4did not loadCornus torreyi, photograph 5did not loadCornus torreyi, photograph 6did not load

Photographs: Elliott Gordon, CC BY, iNaturalist via GBIF; sblumen, CC BY, iNaturalist via GBIF (3); Senna Bryce Robeson, CC BY, iNaturalist via GBIF; Sam Beaumont, CC BY, iNaturalist via GBIF.

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

Elymus glaucus Elymus glaucus Blue wildrye Photo: CC0, author not statedDanthonia californica Danthonia californica California oatgrass Photo: CC BY, Dominic GentilcoreErythranthe microphylla Erythranthe microphylla Small-leaved monkeyflower Photo: CC BY, Sean VanderluitRosa pisocarpa Rosa pisocarpa Cluster rose Photo: CC BY, Aden SommervilleNemophila parviflora Nemophila parviflora Small-flowered nemophila Photo: CC BY, elik03Viola howellii Viola howellii Howell's violet Photo: CC BY, Simone Littledale

Other Cornus 36 in the reference

Cornus alba Cornus alba White dogwood Photo: CC BY, Dmitriy BochkovCornus alternifolia Cornus alternifolia Alternateleaf dogwood Photo: CC BY, Jamie HunterCornus amomum Cornus amomum Silky dogwood Photo: CC BY, Sandy Wolkenberg Cornus × arnoldiana Arnold's dogwood Cornus asperifolia Cornus asperifolia Eastern roughleaf dogwood Photo: CC BY, carterCornus bretschneideri Cornus bretschneideri Bretschneider's Dogwood Photo: CC BY, Jane CharlenCornus canadensis Cornus canadensis Creeping dogwood Photo: CC BY, Arthur WhitingCornus capitata Cornus capitata Bentham's dogwood Photo: CC0, author not statedCornus chinensis Cornus chinensis Cornaceae Photo: CC BY-SA, Krzysztof GolikCornus controversa Cornus controversa Wedding cake tree Photo: CC BY, WATANABE Hitoshi 渡辺仁Cornus disciflora Cornus disciflora Cornaceae Photo: CC BY, Neptalí Ramírez MarcialCornus drummondii Cornus drummondii Rough-leaf dogwood Photo: CC BY, Jeff Hansen all 37 ›

Names & registers

Also known as Cornus alba var. occidentalis; Cornus californica; Cornus californica var. pubescens; Cornus greenei; Cornus occidentalis and 10 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipedia

The record

Family
Cornaceae
Described by
S.Watson
Native to
Alaska, British Columbia, Idaho +6
Wild records
618 in range · 248 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; 23 records within 1 km of a botanic garden, herbarium or zoo left out (16 at a botanic garden or arboretum, 7 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 49.50_-123.125, lapse-corrected -489 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-21
Wikipedia wikipedia answeredasked 2026-10-21
iNaturalist taxon inat.taxon not asked
iNaturalist photographs, wild inat.photos.wild not asked
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 60 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…