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Euphorbia spiralis; photograph (c) Morten Ross, some rights reserved (CC BY) CC BY(c) Morten Ross, some rights reserved (CC BY) · observed growing wild · 2023-12-18

Euphorbia spiralis Balf.f.

Euphorbiaceae · Socotra · listed by its genus as a cactus or succulent

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Euphorbia spiralis, photograph (c) Morten Ross, some rights reserved (CC BY)Euphorbia spiralis, photograph (c) Morten Ross, some rights reserved (CC BY)Euphorbia spiralis, photograph (c) Morten Ross, some rights reserved (CC BY)Euphorbia spiralis, photograph (c) Morten Ross, some rights reserved (CC BY)Euphorbia spiralis, photograph (c) Arabella Willing, some rights reserved (CC BY)Euphorbia spiralis, photograph (c) Morten Ross, some rights reserved (CC BY) 25 photographs ›
Habitat figures
Cold floor (1 night in 100)
19.5°C
Record low 17.7 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
31°C
Apr and May at the habitat CHELSA
Rain a year (median across the range)
248mm
4 months of 25 mm or more in the median year CHELSA
Open-sky light
33–47DLI
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
A rainy season, May and October to December, neither the cool nor the warm half of the year. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Euphorbia spiralis is a species of plant in the family Euphorbiaceae. It is a succulent subshrub or shrub endemic to Socotra in Yemen.

Quoted from Wikipedia, "Euphorbia spiralis", CC BY-SA 4.0.

About the genus · Euphorbia

Euphorbia is a large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae.

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

Cultivation

Grouped as a cactus or succulent, listed under the genus Euphorbia in the archetype table, and Kew describes it as “succulent subshrub or shrub”.

Seasons

The rain rule reads a rainy season with no name: 70% of the median year's rain (178 mm of 228 mm) falls in May and October to December, whose mean temperature, 25.1 °C, is within half a degree of the year's, 25.1 °C, so it is neither the cooler nor the warmer part of the year. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to June and November.

Rain

228 mm in the median year at the habitat, 178 mm of it May and October to December. Wettest month December at 63 mm, driest months (2 at 2 mm); 2 months under 5 mm. Across the grid cells of the range the year's total runs 152 mm to 268 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 248 mm, is the year's rain at the top of the page; the 228 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: 33 to 47 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 31, the highest 90th-percentile month 47).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 19.5 °C, the absolute minimum 17.7 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 31.8 °C. Monthly means: the coldest month's mean nightly low 19.6 °C in January and February (across the grid cells of the range 17.8 °C to 21.4 °C), the warmest month's mean daily high 31.4 °C in May (median year across the grid cells of the range, CHELSA). Cold floor: 19.5 °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: 61 to 67% 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 +196 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 Euphorbia in the archetype table, and Kew describes it as “succulent subshrub or shrub”. 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 Euphorbia spiralis through the yearWarmest months April and May, mean daily high 31 °C; coldest months January and February, mean nightly low 19.6 °C; 228 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.15°20°25°30°35°31.8° 99th-percentile day, NASA POWER17.7° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100mm rainDLI 33–47RH 61–67%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 18 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 °C25 / 24–2626 / 26–2829 / 28–3031 / 30–3231 / 31–3230 / 28–3028 / 27–2928 / 27–2828 / 27–2929 / 28–3027 / 26–2825 / 24–26
Night °C20 / 18–2120 / 18–2121 / 19–2323 / 21–2525 / 24–2725 / 24–2624 / 23–2524 / 22–2523 / 22–2422 / 20–2421 / 19–2321 / 19–22
Rain mm11 / 5–165 / 3–85 / 4–610 / 8–1129 / 19–465 / 3–112 / 2–52 / 1–510 / 5–2640 / 29–4746 / 28–5763 / 36–79
DLI35 / 32–3640 / 38–4145 / 44–4647 / 46–4742 / 41–4337 / 36–3836 / 36–3736 / 36–3638 / 37–3840 / 38–4036 / 34–3733 / 31–35
RH %62 / 59–6562 / 60–6461 / 58–6361 / 59–6265 / 60–6764 / 60–6863 / 59–6864 / 60–6967 / 62–7265 / 62–6663 / 61–6663 / 60–66
How this section is made
Each figure is the median across the 18 grid cells holding the 36 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 1547:4679 (12.625, 53.975). Over 44 years there: absolute minimum 17.7 °C, 1st-percentile night 19.5 °C, 99th-percentile day 31.8 °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 18 distinct grid cells holding 36 of the 36 in-range records; extremes and elevation at the typical cell 1547:4679 (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 12.50_53.750, lapse-corrected +196 m at 6.5 °C/km. Elevation: ETOPO 2022, 330 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.
NativeSocotra · 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 marker12.53, 54.279 · in the densest population, 38 records (100% of those in range)
Kew's description“succulent subshrub or shrub” · “desert or dry shrubland” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 38 georeferenced records inside the native range; the climate across the range on the 36 of them placed to within 10 km; the map shows only the 10 openly licensed ones, which alone would put the marker 3 km away. 2 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 38 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Euphorbia spiralis, photograph 1did not loadEuphorbia spiralis, photograph 2did not loadEuphorbia spiralis, photograph 3did not loadEuphorbia spiralis, photograph 4did not loadEuphorbia spiralis, photograph 5did not loadEuphorbia spiralis, photograph 6did not load

Photographs: (c) Morten Ross, some rights reserved (CC BY) (5); (c) Arabella Willing, some rights reserved (CC BY).

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

Monolluma socotrana Apocynaceae Withania riebeckii Withania riebeckii Solanaceae Photo: CC BY, Morten RossDracaena cinnabari Dracaena cinnabari Socotra dragontree Photo: CC BY, Павлик ЛисицынJatropha unicostata Jatropha unicostata Sibru Photo: CC BY, Arabella WillingExacum affine Exacum affine German-violet Photo: CC BY, Павлик ЛисицынEuphorbia schimperi Euphorbia schimperi Euphorbiaceae Photo: CC BY, Morten Ross

Other Euphorbia 400 in the reference

Euphorbia abdelkuri Euphorbia abdelkuri Abd al Kuri euphorbia Photo: CC BY-SA, Stan ShebsEuphorbia abyssinica Euphorbia abyssinica Abyssinian spurge Photo: CC BY-SA, Frank VincentzEuphorbia acanthothamnos Euphorbia acanthothamnos Greek spiny spurge Photo: CC BY, Eleftherios KatsillisEuphorbia adenensis Euphorbia adenensis Euphorbiaceae Photo: CC BY, Joey BomEuphorbia aeruginosa Euphorbia aeruginosa Miniature Saguaro Photo: CC0, author not statedEuphorbia aggregata Euphorbia aggregata Pincushion euphorbia Photo: CC BY-SA, Frank VincentzEuphorbia albipollinifera Euphorbia albipollinifera Euphorbiaceae Photo: CC BY-SA, Frank VincentzEuphorbia alfredii Euphorbia alfredii Euphorbiaceae Photo: CC BY-SA, Frank VincentzEuphorbia alluaudii Euphorbia alluaudii Euphorbiaceae Photo: CC BY, amantedarmaninEuphorbia ambovombensis Euphorbia ambovombensis Euphorbiaceae Photo: CC BY-SA, Frank VincentzEuphorbia ammak Euphorbia ammak Euphorbiaceae Photo: CC BY-SA, Frank VincentzEuphorbia ampliphylla Euphorbia ampliphylla Euphorbiaceae Photo: CC BY-SA, Medium69 (William Crochot) all 401 ›

Names & registers

Also known as Euphorbia septemsulcata. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Euphorbiaceae
Described by
Balf.f.
Native to
Socotra
Wild records
38 in range · 10 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
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 12.50_53.750, lapse-corrected +196 m at 6.5 °C/km
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 2026-10-22none of the photographs on this page is credited to GBIF: those shown are other sources', and GBIF's were the same photographs or were set aside by the photograph rules
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 3 datasets via GBIF.org; each carries its own licence.

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