''Vachellia sphaerocephala'', the bull's horn thorn or bee wattle, is a plant species in the family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

. 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 The acacia ant (''Pseudomyrmex ferruginea'') is a species of ant of the genus ''Pseudomyrmex''. These arboreal, wasp-like ants have an orange-brown body around 3 mm in length and very large eyes. The acacia ant is best known and named for ...

''. This tree is endemic to

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

.Encyclopedia of Life
/ref>

References

sphaerocephala {{Mimosoideae-stub