Species
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Vachellia karroo (Hayne) Banfi & Galasso

Acacia, Cape Acacia, Cape Mimosa, Cape Thorn

Climate known 54 photographs
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Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.

Summary

Vachellia karroo, commonly known as the sweet thorn, common acacia, Karoo thorn, Cape gum or cockspur thorn, is a species of Vachellia, in the Mimosa sub-family (Mimosoideae) of the Fabaceae or pea family, which is native to southern Africa from southern Angola east to Mozambique, and south to South Africa.

Text from Wikipedia, “Vachellia karroo”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Vachellia

Vachellia is a genus of flowering plants in the legume family, Fabaceae, commonly known as thorn trees or acacias. It belongs to the subfamily Mimosoideae. Its species were considered members of genus Acacia until 2009. More on Wikipedia ›

The opening of Wikipedia, “Vachellia”, CC BY-SA 4.0, quoted as written.

Family
Fabaceae
Described by
(Hayne) Banfi & Galasso
Native to
Angola, Malawi, Mozambique +11
Wild records
1830 in range· 200 open

At a glance

Warmest month
28°C
Jan, mean day; nights 16 °C (CHELSA)
Rain
514mm/yr
9 wet months · peak Nov 66 mm (CHELSA)
Light
19–45DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Rain rule: a summer growing season, April to October in the northern hemisphere (October to April at the habitat, southern). Habitat rain 514 mm a year, wettest November at 66 mm, driest July at 19 mm (habitat calendar, southern hemisphere). Open sky over the habitat: 19 to 45 mol/m²/day. Cold floor -0.1 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Acacia capensis (Burm.f.) Burch.; Acacia dekindtiana A.Chev.; Acacia hirtella E.Mey.; Acacia hirtella Willd.; Acacia hirtella var. hirtella and 12 more.

Cultivation

Its year Rain rule: a summer growing season, April to October in the northern hemisphere (October to April at the habitat, southern).

This species’ habitat figures, and what two fixed rules read from them.

The rain rule reads a summer growing season: 70% of the year's rain (395 mm of 514 mm) falls in October to April, warmer than the year (wet-season mean 19.9 °C against a yearly mean of 17.4 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: April to October.

Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: 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 gives a season to reverse. A reading of the curves, not an observation of the plant.

Rain Habitat rain 514 mm a year, wettest November at 66 mm, driest July at 19 mm (habitat calendar, southern hemisphere).

This species’ habitat figures, with their source.

514 mm a year at the habitat, 395 mm of it October to April. Wettest month November at 66 mm, driest July at 19 mm. Across the envelope cells the year's total runs 295 mm to 861 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, southern hemisphere).

CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light Open sky over the habitat: 19 to 45 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 19 to 45 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 17, the highest 90th-percentile month 52).

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.

Warmth and air Cold floor -0.1 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is -0.1 °C, the absolute minimum -3.5 °C, about 4 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.9 °C. Monthly means: coldest night 6.0 °C in July (across the envelope cells 2.9 °C to 11.5 °C), warmest day 27.6 °C in January (median year across the envelope cells, CHELSA). Cold floor: -0.1 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 52 to 59% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.

CHELSA relative humidity, median year across the envelope cells.

The figures the cards read from are in Climate below, and where they came from in Natural habitat.

Climate across the habitat

Habitat climate through the yearMean day from 19 °C in Jun to 28 °C in Jan; mean night from 6 °C in Jul to 17 °C in Feb. The cold quarter, Jun to Aug, is the three months around the coldest night. 514 mm of rain a year, most in Nov. The bands show the 10th to 90th percentile across 1097 habitat cells. Over 44 years at the typical cell the absolute minimum was -3.5 °C and the 99th-percentile day 37.9 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-10°10°20°30°40°frost37.9° 99th-percentile day (undated)-3.5° lowest night in 44 yrs (undated)°C · day and nightcold quarter0255075100125150mm rainDLI 19–45RH 52–59 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 1097 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C28 / 25–3128 / 25–3026 / 24–2824 / 22–2622 / 19–2319 / 16–2119 / 16–2120 / 18–2222 / 20–2523 / 21–2725 / 22–2827 / 24–30
Night °C16 / 14–1917 / 15–2015 / 13–1913 / 10–1710 / 7–147 / 3–126 / 3–127 / 5–129 / 7–1412 / 9–1513 / 11–1715 / 13–18
Rain mm57 / 25–12957 / 24–11260 / 33–9641 / 27–6222 / 13–3921 / 8–4019 / 3–4029 / 7–5428 / 12–5656 / 24–9066 / 28–11458 / 28–118
DLI43 / 39–5240 / 35–4634 / 31–3827 / 25–3222 / 20–2819 / 17–2521 / 19–2725 / 23–3232 / 30–3938 / 34–4342 / 38–4945 / 40–52
RH %58 / 52–6459 / 52–6459 / 53–6457 / 52–6254 / 50–5852 / 50–5552 / 48–5553 / 47–5755 / 46–6057 / 50–6257 / 51–6258 / 51–63

Each figure is the median across the 1097 grid cells holding the 1818 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 2290:3927 (-24.525, 16.375). Over 44 years there: absolute minimum -3.5 °C, 1st-percentile night -0.1 °C, 99th-percentile day 37.9 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 1097 distinct grid cells holding the 1818 in-range records; extremes and elevation at the typical cell 2290:3927 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell -24.50_16.250, lapse-corrected +155 m at 6.5 °C/km. Elevation: ETOPO 2022, 1455 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 every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeAngola, Malawi, Mozambique, Zambia, Zimbabwe, Botswana, Cape Provinces, Caprivi Strip, Lesotho, Namibia, KwaZulu-Natal, Free State, Swaziland, Northern Provinces· introduced: Baleares, Corse, Portugal, Sardegna, Spain, Italy, Sicilia, Algeria, Libya, Morocco, Tunisia, St.Helena, Mauritius, Cyprus, Iraq, Palestine, Turkey, Myanmar, Queensland, Western Australia, Bolivia, Argentina Northeast, Chile Central, Paraguay
Kew's description“shrub or tree” · “desert or dry shrubland”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker-33.401, 26.445 · in the densest population, 1008 records (55% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 1830 georeferenced records inside the native range; the map shows only the 200 openly licensed ones, which alone would put the marker 34 km away. 95 records outside the range (gardens, roadsides, misidentifications) ignored. 12 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 1830 in-range records; it decides nothing.

Photographs

Vachellia karrooVachellia karrooVachellia karrooVachellia karrooVachellia karrooVachellia karrooVachellia karrooVachellia karroo

Photographs: no rights reserved · CC0 (6); (c) Alan Manson, some rights reserved (CC BY) (2).

Photographs: iNaturalist did not answer when this page was built; what is shown came from the sources that did.

Papers naming this species

Works whose title or abstract names Vachellia karroo, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Fungal Planet description sheets: 1436–1477
Yu Pei Tan, S.L. Bishop-Hurley, Roger G. Shivas, Don A. Cowan (2022) · Persoonia - Molecular Phylogeny and Evolution of Fungi
Palaeoecology of giraffe tracks in Late Pleistocene aeolianites on the Cape south coast
Charles Helm, Hayley C. Cawthra, Richard M. Cowling, Jan C. De Vynck (2018) · South African Journal of Science
Ethnobotanical review of plants used for the management and treatment of childhood diseases and well-being in South Africa
Peter Tshepiso Ndhlovu, Abiodun Olusola Omotayo, Wilfred Otang-Mbeng, Adeyemi O. Aremu (2020) · South African Journal of Botany
Both Alpha- and Beta-Rhizobia Occupy the Root Nodules of Vachellia karroo in South Africa
Chrizelle W. Beukes, F.S. Boshoff, Francina L. Phalane, Ahmed Idris Hassen (2019) · Frontiers in Microbiology
Effect of Soil Type: Qualitative and Quantitative Analysis of Phytochemicals in Some Browse Species Leaves Found in Savannah Biome of South Africa
Humbelani Silas Mudau, Hilda Kwena Mokoboki, Khuliso Emmanuel Ravhuhali, Zimbili Mkhize (2022) · Molecules
Commercialization Potential of Six Selected Medicinal Plants Commonly Used for Childhood Diseases in South Africa: A Review
Peter Tshepiso Ndhlovu, Abiodun Olusola Omotayo, Wilfred Otang-Mbeng, Adeyemi O. Aremu (2021) · Sustainability
Response of photosynthesis, growth and water relations of a savannah-adapted tree and grass grown across high to low CO2
Joe Quirk, Chandra Bellasio, David Johnson, David J. Beerling (2019) · Annals of Botany

Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.

Other Vachellia 3 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild answeredcarried from build of 2026-09-19; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-19; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 41 datasets via GBIF.org; each carries its own licence.