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Rhododendron caucasicum; photograph (c) Виктория Билоус, some rights reserved (CC BY) CC BY(c) Виктория Билоус, some rights reserved (CC BY) · observed growing wild · 2022-07-10

Rhododendron caucasicum Pall.

Georgian Snow Rose

Ericaceae · North Caucasus, Transcaucasus +1 · listed by its genus as a temperate garden plant

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Rhododendron caucasicum, photograph (c) Виктория Билоус, some rights reserved (CC BY)Rhododendron caucasicum, photograph (c) Виктория Билоус, some rights reserved (CC BY)Rhododendron caucasicum, photograph (c) Виктория Билоус, some rights reserved (CC BY)Rhododendron caucasicum, photograph (c) Виктория Билоус, some rights reserved (CC BY)Rhododendron caucasicum, photograph (c) andreikayak, some rights reserved (CC BY)Rhododendron caucasicum, photograph (c) andreikayak, some rights reserved (CC BY) 52 photographs ›
Habitat figures
Coldest month, mean nightly low
-14.1°C
Jan at the habitat, not a floor; extremes not used (the weather cell's ground is too far off) CHELSA
Warmest month, mean daily high
15°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
2,069mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
11–38DLI
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.

Summary

Rhododendron caucasicum, the Caucasian rhododendron or the Georgian snow rose, is a species of flowering plant in the genus Rhododendron native to the Transcaucasus and Anatolia. Its hybrid cultivar 'Christmas Cheer' has gained the Royal Horticultural Society's Award of Garden Merit.

Quoted from Wikipedia, "Rhododendron caucasicum", CC BY-SA 4.0.

About the genus · Rhododendron

Rhododendron, from Ancient Greek ῥόδον (rhódon), meaning "rose", and δένδρον (déndron), meaning "tree", is a very large genus of about 1,024 species of woody plants in the heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan region, but smaller numbers occur elsewhere in Asia, and in North America, Europe and Australia.

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

Cultivation

Grouped as a temperate garden plant, listed under the genus Rhododendron 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 (1,487 mm of 1,995 mm) takes 8 months, April to November. Mean temperature moves 21.6 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: October to May.

Rain

1,995 mm in the median year at the habitat, 1,487 mm of it April to November. Wettest month June at 223 mm, driest month February at 108 mm. Across the grid cells of the range the year's total runs 1,197 mm to 2,935 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 2,069 mm, is the year's rain at the top of the page; the 1,995 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: 11 to 38 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 8, the highest 90th-percentile month 41).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low -14.1 °C in January (across the grid cells of the range -18.9 °C to -9.4 °C), the warmest month's mean daily high 15.2 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is -14.1 °C, the coldest month's mean nightly low, January, 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: 58 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. 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 Rhododendron 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 Rhododendron caucasicum through the yearWarmest months July and August, mean daily high 15 °C; coldest month January, mean nightly low -14.1 °C; 1,995 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, northern hemisphere.-20°-10°0°10°20°30°frost°C · day and nightcold quarter0100200300400mm rainDLI 11–38RH 58–63%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 282 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 °C-7 / -11–-2-6 / -10–-1-2 / -6–23 / -1–88 / 4–1312 / 9–1715 / 12–2015 / 12–2011 / 8–166 / 2–110 / -5–5-5 / -10–0
Night °C-14 / -19–-9-14 / -18–-9-10 / -15–-6-5 / -9–-1-1 / -6–33 / -1–77 / 3–117 / 3–113 / -2–7-2 / -7–2-9 / -13–-4-12 / -17–-8
Rain mm124 / 53–265108 / 55–221136 / 76–231174 / 106–231196 / 139–249223 / 158–290197 / 126–254185 / 116–243170 / 92–238176 / 88–281166 / 76–325140 / 56–292
DLI13 / 10–1619 / 16–2327 / 24–3133 / 30–3737 / 34–4138 / 36–4038 / 35–4035 / 32–3727 / 25–3020 / 17–2314 / 11–1711 / 8–14
RH %60 / 57–6360 / 58–6360 / 58–6361 / 59–6362 / 60–6463 / 60–6562 / 60–6562 / 59–6460 / 57–6359 / 57–6258 / 56–6259 / 57–62

The daily extremes were not used: the correction for elevation, +1124 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 -27.0 °C, 1st-percentile night -20.7 °C.

How this section is made
Each figure is the median across the 282 grid cells holding the 913 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 963:4462 (41.825, 43.125). 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 282 distinct grid cells holding 913 of the 913 in-range records; extremes and elevation at the typical cell 963:4462 (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 42.00_43.125, lapse-corrected +1124 m at 6.5 °C/km. Elevation: ETOPO 2022, 2054 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.
NativeNorth Caucasus, Transcaucasus, Turkey · 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 marker43.524, 41.163 · in the densest population, 616 records (62% 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 998 georeferenced records inside the native range; the climate across the range on the 913 of them placed to within 10 km; the map shows only the 360 openly licensed ones, which alone would put the marker 12 km away. 5 records outside the WCVP native range not used. 85 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 998 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Rhododendron caucasicum, photograph 1did not loadRhododendron caucasicum, photograph 2did not loadRhododendron caucasicum, photograph 3did not loadRhododendron caucasicum, photograph 4did not loadRhododendron caucasicum, photograph 5did not loadRhododendron caucasicum, photograph 6did not load

Photographs: (c) Виктория Билоус, some rights reserved (CC BY) (4); (c) andreikayak, some rights reserved (CC BY) (2).

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

Sedum gracile Sedum gracile Crassulaceae Photo: CC BY, Юлия ЗахаренкоPrimula amoena Primula amoena Caucasian primrose Photo: CC BY, Екатерина КравцоваCampanula tridentata Campanula tridentata Campanulaceae Photo: CC BY, Екатерина КравцоваCherleria circassica Cherleria circassica Caryophyllaceae Photo: CC BY, Юлия ЗахаренкоPrimula auriculata Primula auriculata Primulaceae Photo: CC BY, Louis AuregliaSwertia iberica Swertia iberica Gentianaceae Photo: CC BY, Илья Руденко

Other Rhododendron 574 in the reference

Rhododendron aberconwayi Rhododendron aberconwayi Ericaceae Photo: Public domain, Daderot Rhododendron abietifolium Ericaceae Rhododendron acrophilum Ericaceae Rhododendron adamsii Rhododendron adamsii Sagan Dalya Photo: CC BY, Valentin KosterinRhododendron adenogynum Rhododendron adenogynum Ericaceae Photo: CC BY-SA, Kurt StüberRhododendron adenopodum Rhododendron adenopodum Ericaceae Photo: CC BY-SA, Ulf EliassonRhododendron adenosum Rhododendron adenosum Ericaceae Photo: CC0, DaderotRhododendron aeruginosum Rhododendron aeruginosum Ericaceae Photo: CC BY, Siddarth MachadoRhododendron aganniphum Rhododendron aganniphum Ericaceae Photo: CC0, Daderot Rhododendron agathodaemonis Ericaceae Rhododendron alabamense Rhododendron alabamense Alabama azalea Photo: CC BY, Rob JohnRhododendron albiflorum Rhododendron albiflorum White rhododendron Photo: CC0, author not stated all 575 ›

Names & registers

Also known as Azalea caucasica; Rhododendron caucaseum; Rhododendron caucasicum f. flavidum; Rhododendron caucasicum f. stramineum; Rhododendron caucasicum var. albicans and 20 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Ericaceae
Described by
Pall.
Native to
North Caucasus, Transcaucasus, Turkey
Wild records
998 in range · 360 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; 3 records within 1 km of a botanic garden, herbarium or zoo left out (2 at a botanic garden or arboretum, 1 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 42.00_43.125, lapse-corrected +1124 m at 6.5 °C/km; read, and set aside: the correction for elevation, +1124 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 2026-10-22
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 31 datasets via GBIF.org; each carries its own licence.

Cultifolio

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