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Pilosocereus polygonus; photograph (c) Anthony Batista, some rights reserved (CC BY) CC BY(c) Anthony Batista, some rights reserved (CC BY) · observed growing wild · 2025-02-28

Pilosocereus polygonus (Lam.) Byles & G.D.Rowley

Key tree cactus; Deering's tree cactus; Bahama dildo; Robin tree cactus

Cactaceae · Dominican Republic, Haiti · listed by its family as a cactus or succulent

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Pilosocereus polygonus, photograph (c) Mario Guzmán, some rights reserved (CC BY)Pilosocereus polygonus, photograph (c) Mario Guzmán, some rights reserved (CC BY)Pilosocereus polygonus, photograph (c) Mario Guzmán, some rights reserved (CC BY)Pilosocereus polygonus, photograph (c) Dairon Cuevas Riveras, some rights reserved (CC BY-SA)Pilosocereus polygonus, photograph author not stated, no rights reservedPilosocereus polygonus, photograph author not stated, no rights reserved 58 photographs ›
Habitat figures
Cold floor (1 night in 100)
19.2°C
Record low 16.0 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
31°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
1,005mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
28–43DLI
Lowest to highest month (DLI) CHELSA
The year in the habitat's months, not shifted
  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 sharp rainy season, April to June and August to November (the habitat's months, not shifted), in a year of even temperature. rain rule, CHELSA
Not shifted: the shift rule does not apply to this habitat. The chart is in the habitat's months.

Summary

Pilosocereus polygonus is a species of cactus (family Cactaceae). Like all species in the genus Pilosocereus, it has a shrub- or tree-like growth habit. It has been treated very differently at times. In the narrow circumscription adopted here, it is endemic to Hispaniola, a position adopted by Britton and Rose in 1920 and endorsed in a 2019 review of the genus in the Caribbean and northern Andes. More on Wikipedia ›

Quoted from Wikipedia, "Pilosocereus polygonus", CC BY-SA 4.0.

Cultivation

Grouped as a cactus or succulent, listed under the family Cactaceae in the archetype table, and Kew describes it as “succulent tree”.

Seasons

The rain rule reads a sharp season: 70% of the median year's rain (746 mm of 965 mm) falls in April to June and August to November. The temperature curve is flat, 3.5 °C between the warmest and coldest month, so the growing-season rule does not infer a growing season from it. Months are the habitat's, northern hemisphere. The temperature curve moves under 4 °C between the warmest and coldest month, where the shift rule does not apply, so they are not shifted for a collection elsewhere.

Rain

965 mm in the median year at the habitat, 746 mm of it April to June and August to November. Wettest month May at 142 mm, driest month January at 31 mm. Across the grid cells of the range the year's total runs 733 mm to 1,430 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,005 mm, is the year's rain at the top of the page; the 965 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: 28 to 43 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 26, the highest 90th-percentile month 45).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 19.2 °C, the absolute minimum 16.0 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 38.1 °C. Monthly means: the coldest month's mean nightly low 20.5 °C in January (across the grid cells of the range 17.8 °C to 22.9 °C), the warmest month's mean daily high 31.0 °C in July and August (median year across the grid cells of the range, CHELSA). Cold floor: 19.2 °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: 60 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 -497 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 family Cactaceae in the archetype table, and Kew describes it as “succulent tree”. 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 Pilosocereus polygonus through the yearWarmest months July and August, mean daily high 31 °C; coldest month January, mean nightly low 20.5 °C; 965 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°40°38.1° 99th-percentile day, NASA POWER16.0° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200250mm rainDLI 28–43RH 60–63%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 44 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 °C28 / 25–2928 / 25–3028 / 26–3029 / 26–3129 / 27–3130 / 27–3331 / 28–3431 / 28–3430 / 27–3330 / 27–3129 / 26–3028 / 25–29
Night °C21 / 18–2321 / 18–2321 / 18–2322 / 19–2423 / 20–2524 / 21–2624 / 21–2624 / 21–2624 / 21–2623 / 20–2522 / 20–2521 / 18–24
Rain mm31 / 18–9332 / 19–6453 / 36–8281 / 50–130142 / 88–21290 / 58–13262 / 41–8698 / 64–133119 / 94–176133 / 107–18183 / 64–13841 / 23–90
DLI30 / 28–3234 / 32–3638 / 36–4141 / 39–4340 / 38–4343 / 40–4543 / 41–4542 / 40–4339 / 36–4034 / 33–3530 / 28–3228 / 26–31
RH %61 / 59–6360 / 59–6260 / 58–6361 / 59–6463 / 60–6662 / 59–6660 / 57–6461 / 58–6462 / 60–6563 / 61–6662 / 61–6561 / 60–63
How this section is made
Each figure is the median across the 44 grid cells on land that hold in-range records (63 records in those cells; 1 more cell holds records but no land by the elevation layer, so those records sit at sea and the cell is 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 1428:2158 (18.575, -72.075). Over 44 years there: absolute minimum 16.0 °C, 1st-percentile night 19.2 °C, 99th-percentile day 38.1 °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 44 distinct grid cells holding 63 of the 64 in-range records (1 further cell with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1428:2158 (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 18.50_-71.875, lapse-corrected -497 m at 6.5 °C/km. Elevation: ETOPO 2022, 36 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.
NativeDominican Republic, Haiti · introduced: Canary Is., St.Helena · 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 marker18.393, -71.579 · in the densest population, 68 records (96% of those in range)
Kew's description“succulent tree” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 71 georeferenced records inside the native range; the climate across the range on the 63 of them in the land cells it reads, of 64 placed to within 10 km; the map shows only the 31 openly licensed ones, which alone would put the marker 13 km away. 119 records outside the WCVP native range not used. 7 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 71 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Pilosocereus polygonus, photograph 1did not loadPilosocereus polygonus, photograph 2did not loadPilosocereus polygonus, photograph 3did not loadPilosocereus polygonus, photograph 4did not loadPilosocereus polygonus, photograph 5did not loadPilosocereus polygonus, photograph 6did not load

Photographs: (c) Mario Guzmán, some rights reserved (CC BY) (3); (c) Dairon Cuevas Riveras, some rights reserved (CC BY-SA); author not stated, no rights reserved · CC0 (2).

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

Pimenta haitiensis Pimenta haitiensis Jaragua Bay Tree Photo: CC0, author not statedPlumeria filifolia Plumeria filifolia Apocynaceae Photo: CC BY, J. L. Gómez-HechavarríaCylindropuntia caribaea Cylindropuntia caribaea Cactaceae Photo: CC BY, Laurimar SepulvedaCoccothrinax spissa Coccothrinax spissa Swollen Silver Thatch Palm Photo: CC BY-SA, David J. StangPlumeria × stenopetala Plumeria × stenopetala Apocynaceae Photo: CC0, Yolanda M. Leon Parasenegalia skleroxyla Corbano

Other Pilosocereus 20 in the reference

Pilosocereus alensis Pilosocereus alensis Cactaceae Photo: CC BY-SA, Adrian BojorquezPilosocereus armatus Pilosocereus armatus Cactaceae Photo: CC BY, Alex DoylePilosocereus arrabidae Pilosocereus arrabidae Cactaceae Photo: CC0, author not statedPilosocereus azulensis Pilosocereus azulensis Cactaceae Photo: CC BY, Peter A. MansfeldPilosocereus brasiliensis Pilosocereus brasiliensis Cactaceae Photo: CC BY, fmunozPilosocereus catingicola Pilosocereus catingicola Cactaceae Photo: CC0, author not statedPilosocereus chrysacanthus Pilosocereus chrysacanthus Cactaceae Photo: CC BY, Alexis López HernándezPilosocereus chrysostele Pilosocereus chrysostele Cactaceae Photo: CC BY, stephenPilosocereus collinsii Pilosocereus collinsii Cactaceae Photo: CC BY, Carlos Domínguez-RodríguezPilosocereus curtisii Pilosocereus curtisii Cactaceae Photo: CC BY, Jose Luis Leon de la LuzPilosocereus fulvilanatus Pilosocereus fulvilanatus Cactaceae Photo: CC BY, B. PhalanPilosocereus gaumeri Pilosocereus gaumeri Cactaceae Photo: CC BY, Oscar Orlando Vazquez Piña all 21 ›

Names & registers

Also known as Cactus polygonus; Cactus royenii; Cephalocereus monoclonos; Cephalocereus polygonus; Cephalocereus royenii and 15 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Cactaceae
Described by
(Lam.) Byles & G.D.Rowley
Native to
Dominican Republic, Haiti
Wild records
71 in range · 31 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 (3 at a botanic garden or arboretum; 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 18.50_-71.875, lapse-corrected -497 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 25 datasets via GBIF.org; each carries its own licence.

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