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Vachellia sphaerocephala; photograph Anonymous Unknown author, Public domain, via Wikimedia Commons Public domainAnonymous Unknown author, Public domain, via Wikimedia Commons

Vachellia sphaerocephala (Cham. & Schltdl.) Seigler & Ebinger

Bee wattle; Bull's-Horn Acacia; Bull-horn Acacia

Fabaceae · Mexico Northeast, Mexico Gulf +3

Cited as Kew's World Checklist cites it, Vachellia sphaerocephala (Cham. & Schltdl.) Seigler & Ebinger: GBIF's backbone key for this page carries the name with another author, (Schltdl. & Cham.) Seigler & Ebinger.

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Sow seed
Habitat figures
Cold floor (1 night in 100)
11.6°C
Record low 3.5 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
31°C
May at the habitat CHELSA
Rain a year (median across the range)
1,240mm
9 months of 25 mm or more in the median year CHELSA
Open-sky light
24–40DLI
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 September, 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

Vachellia sphaerocephala, the bull's horn thorn or bee wattle, is a plant species in the family Fabaceae. The name comes from the shape of the thorns which do indeed resemble the horns of a bull. The tree has a strong, symbiotic relationship with a species of stinging ant, Pseudomyrmex ferruginea. This tree is endemic to Mexico.

Quoted from Wikipedia, "Vachellia sphaerocephala", CC BY-SA 4.0.

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 ›

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

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (908 mm of 1,243 mm) falls in June to September, warmer than the year (wet-season mean 26.6 °C against a yearly mean of 24.2 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: December to March.

Rain

1,243 mm in the median year at the habitat, 908 mm of it June to September. Wettest month September at 243 mm, driest months (2 at 18 mm). Across the grid cells of the range the year's total runs 1,101 mm to 1,627 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,240 mm, is the year's rain at the top of the page; the 1,243 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: 24 to 40 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 20, the highest 90th-percentile month 42).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 11.6 °C, the absolute minimum 3.5 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 41.6 °C. Monthly means: the coldest month's mean nightly low 17.0 °C in January (across the grid cells of the range 12.8 °C to 19.1 °C), the warmest month's mean daily high 31.2 °C in May (median year across the grid cells of the range, CHELSA). Cold floor: 11.6 °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 66% 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 -921 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.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Vachellia sphaerocephala through the yearWarmest month May, mean daily high 31 °C; coldest month January, mean nightly low 17.0 °C; 1,243 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.0°10°20°30°40°50°41.6° 99th-percentile day, NASA POWER3.5° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400mm rainDLI 24–40RH 61–66%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 39 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 °C24 / 22–2626 / 23–2828 / 25–3030 / 27–3231 / 28–3330 / 27–3229 / 26–3130 / 26–3129 / 25–3028 / 25–2926 / 24–2824 / 23–27
Night °C17 / 13–1918 / 14–2019 / 15–2121 / 17–2323 / 18–2523 / 19–2523 / 18–2523 / 18–2523 / 18–2521 / 17–2319 / 15–2118 / 14–20
Rain mm26 / 15–4718 / 12–4318 / 11–4230 / 18–5656 / 50–103218 / 157–281242 / 166–359205 / 166–311243 / 202–307124 / 94–15740 / 19–6523 / 13–47
DLI25 / 21–3429 / 26–3835 / 32–4139 / 38–4240 / 38–4238 / 36–3938 / 36–3937 / 36–3833 / 31–3430 / 29–3227 / 24–3224 / 20–32
RH %63 / 59–6662 / 58–6561 / 57–6461 / 58–6562 / 59–6665 / 63–6865 / 62–6765 / 63–6766 / 64–6863 / 62–6762 / 60–6662 / 59–67
How this section is made
Each figure is the median across the 39 grid cells holding the 47 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 1413:1668 (19.325, -96.575). Over 44 years there: absolute minimum 3.5 °C, 1st-percentile night 11.6 °C, 99th-percentile day 41.6 °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 39 distinct grid cells holding 47 of the 47 in-range records; extremes and elevation at the typical cell 1413:1668 (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 19.50_-96.875, lapse-corrected -921 m at 6.5 °C/km. Elevation: ETOPO 2022, 212 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.
NativeMexico Northeast, Mexico Gulf, Mexico Southwest, Mexico Southeast, Honduras · introduced: Pakistan, Trinidad-Tobago · 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 marker19.33, -96.481 · in the densest population, 52 records (63% of those in range)
Kew's description“shrub or tree” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 82 georeferenced records inside the native range; the climate across the range on the 47 of them placed to within 10 km; the map shows only the 64 openly licensed ones, which alone would put the marker 4 km away. 16 records outside the WCVP native range not used. 35 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 82 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

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

Cephalocereus scoparius Cephalocereus scoparius Cactaceae Photo: CC BY, Tereso Hernández Morales Zamia inermis Zamiaceae Colubrina elliptica Colubrina elliptica Soldierwood Photo: CC BY, Tom FieldCalliandra tergemina Calliandra tergemina Pink Powderpuff Photo: CC BY, Francisco Farriols SarabiaArdisia escallonioides Ardisia escallonioides Dogberry Photo: CC BY, Tom FieldEchites panduratus Echites panduratus Apocynaceae Photo: CC BY, Alexis López Hernández

Other Vachellia 38 in the reference

Vachellia abyssinica Vachellia abyssinica Nyanga flat-top Photo: CC BY, Edmundas GreimasVachellia albicorticata Vachellia albicorticata Fabaceae Photo: CC BY, Silvia TenVachellia aroma Vachellia aroma Fabaceae Photo: CC BY, Rocío Esmeralda PoseVachellia astringens Vachellia astringens Fabaceae Photo: CC BY, RAPVachellia bravoensis Vachellia bravoensis Huisachillo Photo: CC BY, Clifton Ladd, C.W.B.Vachellia campeachiana Vachellia campeachiana Boat-spine Acacia Photo: CC0, Sinaloa SilvestreVachellia caven Vachellia caven Roman cassie Photo: CC BY, Karim HaddadVachellia choriophylla Vachellia choriophylla Cinnecord Photo: CC BY, Tom FieldVachellia collinsii Vachellia collinsii Bull horn acacia Photo: CC BY, Eamon CorbettVachellia constricta Vachellia constricta Whitethorn acacia Photo: CC BY, CK2AZVachellia cornigera Vachellia cornigera Bullhorn wattle Photo: CC BY, Carlos Domínguez-RodríguezVachellia cucuyo Vachellia cucuyo Fabaceae Photo: CC0, Yolanda M. Leon all 39 ›

Names & registers

Also known as Acacia dolichocephala; Acacia sphaerocephala; Acacia veracruzensis; Inga cornigera. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Fabaceae
Described by
(Cham. & Schltdl.) Seigler & Ebinger
Native to
Mexico Northeast, Mexico Gulf, Mexico Southwest +2
Wild records
82 in range · 64 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 2026-10-22GBIF's key 3795398 is Vachellia sphaerocephala (Schltdl. & Cham.) Seigler & Ebinger; the page links Kew's Vachellia sphaerocephala (Cham. & Schltdl.) Seigler & Ebinger, and the name is cited as Kew cites it
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; 1 record within 1 km of a botanic garden, herbarium or zoo left out (1 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 19.50_-96.875, lapse-corrected -921 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild nothing to reportasked 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 nothing to reportasked 2026-10-22
Wikimedia Commons commons 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 21 datasets via GBIF.org; each carries its own licence.

Cultifolio

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