Ceanothus velutinus Douglas ex Hook.
Big buck-brush; Snowbrush; Tobacco brush; Snowbrush ceanothus
Cited as Kew's World Checklist cites it, Ceanothus velutinus Douglas ex Hook.: GBIF's backbone key for this page carries the name with another author, Douglas.





79 photographs › At a glance
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- May, shaded
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- Nov, shaded
- Dec, shaded
Summary
Ceanothus velutinus, with the common names snowbrush ceanothus, red root, tobacco brush, and sticky laurel, is a species of shrub in the family Rhamnaceae. It is native to western North America from British Columbia to California to Colorado.
Quoted from Wikipedia, "Ceanothus velutinus", CC BY-SA 4.0.
About the genus · Ceanothus
Ceanothus is a genus of about 50–60 species of nitrogen-fixing shrubs and small trees in the buckthorn family (Rhamnaceae). Common names for members of this genus are buckbrush, California lilac, soap bush, or just ceanothus. The genus is native to North America, ranging from Canada and the United States south through Mexico to Panama, with the center of diversity in the California floristic province of the western United States and Mexico, where around ~42 species are endemic out of the roughly ~58 species in the genus. More on Wikipedia ›
Quoted from Wikipedia, "Ceanothus", CC BY-SA 4.0.
Cultivation
Seasons
The rain rule reads a rainy season and no growing season: 70% of the median year's rain (643 mm of 844 mm) falls in November to May, the cooler part of the year, but the mean nightly low is below freezing in February, March, April, May, 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 November.
Rain
844 mm in the median year at the habitat, 643 mm of it November to May. Wettest month December at 120 mm, driest month August at 24 mm. Across the grid cells of the range the year's total runs 461 mm to 1,837 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 879 mm, is the year's rain at the top of the page; the 844 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: 10 to 49 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
Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -13.1 °C, the absolute minimum -22.3 °C, 6,869 frost nights in 44 years, 156.1 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 33.8 °C. Monthly means: the coldest month's mean nightly low -7.9 °C in December (across the grid cells of the range -13.1 °C to -2.0 °C), the warmest month's mean daily high 24.9 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -13.1 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).
Relative humidity at the habitat: 49 to 63% 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 -221 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
Mean daily high from -1 °C in Dec to 25 °C in Jul and Aug; mean nightly low from -8 °C in Dec to 10 °C in Jul and Aug. The cold quarter, Nov to Jan, is the three months around the coldest month's mean nightly low. 844 mm of rain in the median year (the twelve monthly medians added), the wettest month Dec. The bands show the 10th to 90th percentile across 1298 habitat cells. Over 44 years at a typical spot in the range (NASA POWER) the absolute minimum was -22.3 °C and the 99th-percentile day 33.8 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.
Figures by month
| Figure | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 0 / -4–6 | 2 / -2–7 | 5 / 2–10 | 9 / 6–13 | 15 / 11–18 | 20 / 17–23 | 25 / 21–28 | 25 / 21–28 | 20 / 17–23 | 13 / 9–17 | 4 / 1–9 | -1 / -4–6 |
| Night °C | -7 / -12–-2 | -7 / -12–-2 | -4 / -8–0 | -2 / -5–2 | 2 / -2–6 | 6 / 3–10 | 10 / 7–13 | 10 / 7–13 | 7 / 3–10 | 2 / -2–6 | -4 / -9–1 | -8 / -13–-2 |
| Rain mm | 111 / 40–282 | 86 / 33–230 | 83 / 36–208 | 67 / 32–132 | 66 / 37–114 | 50 / 23–98 | 25 / 9–61 | 24 / 10–56 | 37 / 18–72 | 65 / 34–148 | 110 / 44–283 | 120 / 47–326 |
| DLI | 12 / 8–17 | 18 / 14–24 | 27 / 22–34 | 36 / 32–42 | 43 / 38–48 | 47 / 41–52 | 49 / 43–53 | 43 / 37–47 | 33 / 28–38 | 22 / 16–28 | 13 / 8–19 | 10 / 6–15 |
| RH % | 63 / 56–67 | 61 / 57–64 | 59 / 56–63 | 56 / 53–61 | 55 / 51–60 | 53 / 46–59 | 49 / 41–56 | 49 / 41–55 | 51 / 44–57 | 55 / 49–61 | 62 / 55–67 | 63 / 57–68 |
How this section is made
Natural habitat
How this section is made
Photographs
Photographs: (c) machaut2, some rights reserved (CC BY) (2); author not stated, no rights reserved · CC0 (2); (c) Caleb Catto, some rights reserved (CC BY); (c) P Holroyd, some rights reserved (CC BY).
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Silene douglasii Douglas' campion Photo: CC0, author not stated
Hieracium scouleri Scouler's hawkweed Photo: CC BY, cigazze
Pterospora andromedea Pinedrops Photo: CC0, author not stated Veronica missurica Plantaginaceae
Madia glomerata Mountain tarweed Photo: CC BY, Zach Earl
Polystichum scopulinum Mountain holly fern Photo: CC BY, crothfelsOther Ceanothus 38 in the reference
Ceanothus americanus New Jersey tea Photo: CC BY, WF_MI
Ceanothus arboreus Felt-leaf ceanothus Photo: CC BY, Matt Berger
Ceanothus caeruleus Rhamnaceae Photo: CC BY, Neptalí Ramírez Marcial
Ceanothus cordulatus Mountain whitethorn Photo: CC BY-SA, Nancy Overholtz
Ceanothus crassifolius Hoary-leaf ceanothus Photo: CC0, author not stated
Ceanothus cuneatus Buckbrush Photo: CC BY, Devon Bradley
Ceanothus cyaneus Lakeside ceanothus Photo: CC BY, Matt Berger
Ceanothus dentatus Sandscrub ceanothus Photo: CC BY, Ryan Donnelly
Ceanothus divergens Calistoga ceanothus Photo: CC BY, Peter Warner
Ceanothus fendleri Fendler buckbrush Photo: CC BY, Matt Berger
Ceanothus foliosus Wavyleaf ceanothus Photo: CC BY, jbradbury
Ceanothus gloriosus Point Reyes ceanothus Photo: CC BY, Peter Brastow all 39 ›Names & registers
Also known as Ceanothus grandis. (GBIF Backbone)
The record
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 answeredasked 2026-10-21GBIF's key 7723763 is Ceanothus velutinus Douglas; the page links Kew's Ceanothus velutinus Douglas ex Hook., and the name is cited as Kew cites itgbif.synonyms answeredasked 2026-10-21gbif.vernacular answeredasked 2026-10-21names fetched 2026-10-21wcvp.distribution answeredas of 2026-06-04gbif.occurrences answeredasked 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 900 records of GBIF's key 3039312, Ceanothus velutinus Douglas ex Hook. (Kew's file holds it as Ceanothus velutinus Douglas ex Hook. (accepted)): GBIF occurrence search API; 4 records within 1 km of a botanic garden, herbarium or zoo left out (3 at a botanic garden or arboretum, 1 at a herbarium; Wikidata's list)climate answeredasked 2026-10-21climate.extremes answeredasked 2026-10-21NASA POWER (MERRA-2) daily 1981–2024, cell 38.50_-119.375, lapse-corrected -221 m at 6.5 °C/kmwikidata answeredasked 2026-10-21found by its label; its IPNI identifier 30066955-2 is Kew's for Ceanothus velutinus Douglas ex Hook.wikipedia answeredasked 2026-10-21inat.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 2026-10-22inat.photos.cultivated not askedgbif.media answeredasked 2026-10-21read from the page's key and its other keys: 46 from GBIF's key 3039312openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshotEvery 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 92 datasets via GBIF.org; each carries its own licence.






