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Rosa squarrosa; photograph (c) Santiago Martín-Bravo, some rights reserved (CC BY) CC BY(c) Santiago Martín-Bravo, some rights reserved (CC BY) · observed growing wild · 2024-12-08

Rosa squarrosa (A.Rau) Boreau

Rosaceae · Great Britain, Ireland +5 · listed by its genus as a temperate garden plant

Cited as Kew's World Checklist cites it, Rosa squarrosa (A.Rau) Boreau: GBIF's backbone key for this page carries the name with another author, Rau.

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Rosa squarrosa, photograph (c) Santiago Martín-Bravo, some rights reserved (CC BY)Rosa squarrosa, photograph (c) Santiago Martín-Bravo, some rights reserved (CC BY)Rosa squarrosa, photograph (c) Santiago Martín-Bravo, some rights reserved (CC BY)Rosa squarrosa, photograph (c) Santiago Martín-Bravo, some rights reserved (CC BY)Rosa squarrosa, photograph (c) Santiago Martín-Bravo, some rights reserved (CC BY)Rosa squarrosa, photograph Bram vd Bergh, CC0, via GBIF 15 photographs ›
Habitat figures
Cold floor (1 night in 100)
-7.8°C
Record low -17.0 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
23°C
Jul at the habitat CHELSA
Rain a year (median across the range)
791mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
4–33DLI
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
Rain spread: 70% of the median year's rain takes 8 months, so no short rainy season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Cultivation

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

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (566 mm of 799 mm) takes 8 months, August to January and April to May. Mean temperature moves 14.1 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: February to July and October to November.

Rain

799 mm in the median year at the habitat, 566 mm of it August to January and April to May. Wettest month December at 85 mm, driest month February at 57 mm. Across the grid cells of the range the year's total runs 542 mm to 1,033 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 791 mm, is the year's rain at the top of the page; the 799 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: 4 to 33 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 4, the highest 90th-percentile month 50).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -7.8 °C, the absolute minimum -17.0 °C, 2,408 frost nights in 44 years, 54.7 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 29.5 °C. Monthly means: the coldest month's mean nightly low 0.9 °C in February (across the grid cells of the range -0.2 °C to 3.7 °C), the warmest month's mean daily high 22.6 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -7.8 °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: 60 to 68% 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 -28 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 Rosa in the archetype table, and Kew describes it as “shrub”, “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 Rosa squarrosa through the yearWarmest month July, mean daily high 23 °C; coldest month February, mean nightly low 0.9 °C; 799 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°frost29.5° 99th-percentile day, NASA POWER-17.0° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125150mm rainDLI 4–33RH 60–68%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 28 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 °C6 / 5–117 / 6–1310 / 8–1714 / 10–1818 / 14–2220 / 17–2823 / 19–3222 / 19–3119 / 16–2715 / 12–219 / 8–157 / 5–12
Night °C1 / 0–31 / 0–43 / 1–65 / 2–79 / 5–1012 / 8–1514 / 11–1814 / 11–1811 / 9–158 / 6–114 / 3–72 / 1–4
Rain mm70 / 51–10557 / 44–8259 / 40–8362 / 49–9167 / 46–8258 / 23–8159 / 6–8065 / 7–8465 / 33–8478 / 68–11974 / 67–11985 / 69–136
DLI5 / 5–1510 / 9–2117 / 16–3027 / 25–3732 / 31–4333 / 32–4833 / 31–5028 / 26–4519 / 18–3412 / 11–237 / 6–164 / 4–13
RH %67 / 61–6964 / 58–6762 / 55–6560 / 54–6360 / 53–6260 / 48–6260 / 44–6260 / 45–6362 / 50–6464 / 56–6667 / 60–6968 / 62–70
How this section is made
Each figure is the median across the 28 grid cells holding the 32 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 780:3692 (50.975, 4.625). Over 44 years there: absolute minimum -17.0 °C, 1st-percentile night -7.8 °C, 99th-percentile day 29.5 °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 28 distinct grid cells holding 32 of the 32 in-range records; extremes and elevation at the typical cell 780:3692 (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 51.00_4.375, lapse-corrected -28 m at 6.5 °C/km. Elevation: ETOPO 2022, 9 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.
NativeGreat Britain, Ireland, France, Spain, Sicilia, Algeria, Morocco · 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 marker52.6, -2.799 · in the densest population, 13 records (39% 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 33 georeferenced records inside the native range; the climate across the range on the 32 of them placed to within 10 km; the map shows only the 23 openly licensed ones, which alone would put the marker in the same place. 45 records outside the WCVP native range not used. 1 in-range record is placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stays 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 33 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Rosa squarrosa, photograph 1did not loadRosa squarrosa, photograph 2did not loadRosa squarrosa, photograph 3did not loadRosa squarrosa, photograph 4did not loadRosa squarrosa, photograph 5did not loadRosa squarrosa, photograph 6did not load

Photographs: (c) Santiago Martín-Bravo, some rights reserved (CC BY) (5); Bram vd Bergh, CC0, via GBIF.

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

Silaum silaus Silaum silaus Pepper-saxifrage Photo: CC BY, Augustin SoulardLuronium natans Luronium natans Floating water-plantain Photo: CC0, author not statedCentaurea thuillieri Centaurea thuillieri Meadow Knapweed Photo: CC BY, Norma MalinowskiBromus commutatus Bromus commutatus Meadow brome Photo: CC BY, Наталья ПикаловаPopulus × canescens Populus × canescens Gray poplar Photo: CC0, author not statedAlisma lanceolatum Alisma lanceolatum Narrow-leaved Water-plantain Photo: CC BY, Flavien Saboureau

Other Rosa 126 in the reference

Rosa abietina Rosa abietina Needle rose Photo: CC BY-SA, michele barrereRosa abyssinica Rosa abyssinica Abyssinian rose Photo: CC BY, Jacky JudasRosa acicularis Rosa acicularis Prickly rose Photo: CC BY, Syd CanningsRosa agrestis Rosa agrestis Small-leaved Sweet-briar Photo: CC BY, Bobo-XRosa × alba Rosa × alba White rose of York Photo: CC BY, jamie-aaRosa alberti Rosa alberti Rosaceae Photo: CC BY, Alexander DubyninRosa amblyotis Rosa amblyotis Rosaceae Photo: CC BY-SA, Salicyna Rosa × andegavensis Rosaceae Rosa arkansana Rosa arkansana Prairie rose Photo: CC0, author not statedRosa arvensis Rosa arvensis Field rose Photo: CC BY, David SandlerRosa balsamica Rosa balsamica Round-leaved dog-rose Photo: CC BY-SA, Andrea MoroRosa banksiae Rosa banksiae Banksian rose Photo: CC BY, Janetmhm all 127 ›

Names & registers

Also known as Rosa canina var. biserrata; Crepinia biserrata; Crepinia squarrosa; Rosa aciphylla var. gracilescens; Rosa arvensis f. biserrata and 39 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataiNaturalist

The record

Family
Rosaceae
Described by
(A.Rau) Boreau
Native to
Great Britain, Ireland, France +4
Wild records
33 in range · 23 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 2026-10-22GBIF's key 7699588 is Rosa squarrosa Rau; Kew accepts Rosa squarrosa (A.Rau) Boreau, and the name is cited as Kew accepts it; its synonyms and common names are read from GBIF's Rosa squarrosa (A.Rau) Boreau (10962703), which GBIF files under Rosa canina var. biserrata (Mérat) Chevall. (3002781) too
GBIF synonyms gbif.synonyms answeredasked 2026-10-2256 read from GBIF's Rosa squarrosa (A.Rau) Boreau (10962703), which GBIF files under Rosa canina var. biserrata (Mérat) Chevall. (3002781)
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 51.00_4.375, lapse-corrected -28 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by its label; its POWO identifier 60473660-2 is Kew's for Rosa squarrosa (A.Rau) Boreau
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 9 datasets via GBIF.org; each carries its own licence.

Cultifolio

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