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Trianthema portulacastrum; photograph (c) Bruce Hartman, some rights reserved (CC BY) CC BY(c) Bruce Hartman, some rights reserved (CC BY) · observed growing wild · 2026-08-24

Trianthema portulacastrum L.

Desert horsepurslane; Horse purslane; Black pigweed; Giant pigweed

Aizoaceae · Benin, Burkina +109

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Trianthema portulacastrum, photograph (c) Jo Roberts, some rights reserved (CC BY)Trianthema portulacastrum, photograph (c) Jo Roberts, some rights reserved (CC BY)Trianthema portulacastrum, photograph (c) Jo Roberts, some rights reserved (CC BY)Trianthema portulacastrum, photograph (c) Jo Roberts, some rights reserved (CC BY)Trianthema portulacastrum, photograph (c) Linda Jo Conn, some rights reserved (CC BY)Trianthema portulacastrum, photograph (c) Linda Jo Conn, some rights reserved (CC BY) 66 photographs ›
Habitat figures
Coldest month, mean nightly low
14.3°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
32°C
Jun and Jul at the habitat CHELSA
Rain a year (median across the range)
751mm
6 months of 25 mm or more in the median year CHELSA
Open-sky light
26–44DLI
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
Wet summers: the rain comes June to October, read as a summer growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Trianthema portulacastrum is a species of flowering plant in the ice plant family known by the common names desert horsepurslane, black pigweed, and giant pigweed. It is native to areas of several continents, including Africa and North and South America, and present as an introduced species in many other areas. It grows in a wide variety of habitat types and it can easily take hold in disturbed areas and cultivated land as a weed.

Quoted from Wikipedia, "Trianthema portulacastrum", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (367 mm of 512 mm) falls in June to October, warmer than the year (wet-season mean 27.2 °C against a yearly mean of 23.7 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: December to April.

Rain

512 mm in the median year at the habitat, 367 mm of it June to October. Wettest month September at 98 mm, driest month April at 18 mm. Across the grid cells of the range the year's total runs 196 mm to 1,764 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 751 mm, is the year's rain at the top of the page; the 512 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: 26 to 44 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 19, the highest 90th-percentile month 53).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low 14.3 °C in January (across the grid cells of the range 3.2 °C to 23.0 °C), the warmest month's mean daily high 31.9 °C in June (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 14.3 °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: 54 to 61% 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.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Trianthema portulacastrum through the yearWarmest months June and July, mean daily high 32 °C; coldest month January, mean nightly low 14.3 °C; 512 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, northern hemisphere.0°10°20°30°40°°C · day and nightcold quarter0100200300400mm rainDLI 26–44RH 54–61%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 875 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 °C22 / 15–3024 / 17–3126 / 21–3428 / 24–3730 / 26–3832 / 27–3932 / 26–3831 / 26–3730 / 27–3529 / 25–3226 / 20–3023 / 15–29
Night °C14 / 3–2315 / 5–2317 / 7–2420 / 11–2522 / 15–2624 / 18–2725 / 20–2725 / 19–2724 / 17–2621 / 13–2518 / 8–2315 / 4–23
Rain mm21 / 4–8620 / 4–8020 / 3–9418 / 1–11626 / 1–18066 / 1–27380 / 12–32785 / 22–32098 / 16–23638 / 11–16920 / 6–12320 / 5–100
DLI27 / 20–3533 / 25–3939 / 32–4344 / 35–4844 / 34–5241 / 32–5340 / 27–4838 / 28–4435 / 31–4032 / 29–3728 / 23–3426 / 19–33
RH %57 / 49–6455 / 46–6554 / 43–6554 / 39–6656 / 38–6658 / 37–6760 / 45–6661 / 48–6761 / 45–6758 / 45–6557 / 45–6557 / 49–64

The daily extremes were not used: the correction for elevation, -1147 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 17.3 °C, 1st-percentile night 19.0 °C.

How this section is made
Each figure is the median across the 875 grid cells on land that hold in-range records (1136 records in those cells; 15 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are 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 2035:2056 (-11.775, -77.175). 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 875 distinct grid cells holding 1136 of the 1161 in-range records (15 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 2035:2056 (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 -12.00_-76.875, lapse-corrected -1147 m at 6.5 °C/km. Elevation: ETOPO 2022, 48 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.
NativeBenin, Burkina, The Gambia, Ghana, Guinea-Bissau, Guinea, Ivory Coast, Mali, Mauritania, Nigeria, Niger, Senegal, Togo, Cameroon, Congo, Zaïre, Chad, Djibouti, Eritrea, Somalia, Sudan, Kenya, Tanzania, Angola, Malawi, Mozambique, Northern Provinces, Aldabra, Comoros, Mauritius, Réunion, Rodrigues, Iran, Gulf States, Oman, Saudi Arabia, Yemen, Hainan, China Southeast, Taiwan, Bangladesh, India, Nepal, Pakistan, Sri Lanka, Andaman Is., Cambodia, Myanmar, South China Sea, Thailand, Vietnam, Jawa, Lesser Sunda Is., Malaya, Maluku, Philippines, Sulawesi, New Guinea, Missouri, Oklahoma, New Jersey, Arizona, California, Nevada, Utah, New Mexico, Texas, Arkansas, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Mexico Central, Mexico Northeast, Mexico Gulf, Mexico Northwest, Mexico Southwest, Mexico Southeast, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Aruba, Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is. AB Ant, Netherlands Antilles, Puerto Rico, Turks-Caicos Is., Trinidad-Tobago, Venezuelan Antilles, Windward Is., Venezuela, Bolivia, Colombia, Ecuador, Galápagos, Peru, Argentina Northeast, Argentina Northwest, Paraguay · introduced: St.Helena, Palestine, New South Wales, Northern Territory, Queensland, Western Australia, Hawaii, Colorado, Alabama, Brazil Northeast · 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 marker32.867, -111.567 · in the densest population, 372 records (25% of those in range)
Kew's description“annual or biennial” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1485 georeferenced records inside the native range; the climate across the range on the 1136 of them in the land cells it reads, of 1161 placed to within 10 km; the map shows only the 763 openly licensed ones, which alone would put the marker 700 km away. 209 records outside the WCVP native range not used. 324 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 inside the densest 4° block of the 1485 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Trianthema portulacastrum, photograph 1did not loadTrianthema portulacastrum, photograph 2did not loadTrianthema portulacastrum, photograph 3did not loadTrianthema portulacastrum, photograph 4did not loadTrianthema portulacastrum, photograph 5did not loadTrianthema portulacastrum, photograph 6did not load

Photographs: (c) Jo Roberts, some rights reserved (CC BY) (4); (c) Linda Jo Conn, 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.

Citharexylum berlandieri Citharexylum berlandieri Berlandier's fiddlewood Photo: CC BY, Katie RaneyManihot walkerae Manihot walkerae Walker's manioc Photo: CC BY-SA, Turner BrockmanAsclepias prostrata Asclepias prostrata Prostrate milkweed Photo: CC BY, Reid HardinTillandsia baileyi Tillandsia baileyi Reflexed airplant Photo: CC BY, Reid HardinNephroia diversifolia Nephroia diversifolia Menispermaceae Photo: CC BY, sonnia hillMalvastrum americanum Malvastrum americanum Indian Valley false mallow Photo: CC BY, Em Lamond

Other Trianthema 1 in the reference

Trianthema triquetrum Trianthema triquetrum Red spinach Photo: CC BY, Thomas Mesaglio

Names & registers

Also known as Portulaca axilliflora; Portulaca toston; Portulacastrum monogynum; Tetragonia chisimajensis; Trianthema flexuosum and 7 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Aizoaceae
Described by
L.
Native to
Benin, Burkina, The Gambia +108
Wild records
1485 in range · 763 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; 34 records within 1 km of a botanic garden, herbarium or zoo left out (21 at a botanic garden or arboretum, 3 at a herbarium, 10 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 -12.00_-76.875, lapse-corrected -1147 m at 6.5 °C/km; read, and set aside: the correction for elevation, -1147 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 179 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…