"Acacia farnesiana" var. "guanacastensis" is primarily distinguished by larger leaflets. It remains controversial; most taxonomic authorities in Mexico and Central America recognise this taxon as a full species under either "A. guanacastensis" or "Vachellia guanacastensis", the "Árboles nativos e introduciados de El Salvador" of 2009 subsumed it under "Acacia farnesiana". It is recognised as present in Costa Rica, El Salvador, Guatemala, Nicaragua, and the southern Gulf and southwestern regions of Mexico by the "Kew World Checklist of Selected Plant Families" (2018), but whether the taxon as recognised by the different authorities replaces "Acacia farnesiana" in Central America (but not the Caribbean or South America) or exists sympatrically remains unclear. This has implications for the classification of the extra-American distribution of "A. farnesiana" as the populations growing in Australia and the Philippines have recently (2017) been shown to derive from ancient Central American origins.