Needle Bush or Prickly Acacia (Vachellia farnesiana) cultivated at PROINPA site, Cochabamba, Bolivia. Photographed on 2 December 2008www.inaturalist.org/observations/53795278
The swellings are domatia housing myrmecophile ants which protect the tree. An eastern Africa species, also known as Swollen Thorn and placed in the Vachellia genus by some. Photo from Songea region, Tanzania.