The Online Etymology Dictionary says that the word comes from the "late 14c., "large snake," from Latin boa, type of large serpent mentioned in Pliny's "Natural History;" origin unknown (in medieval folk etymology the name was associated with Greek bous "ox")."
Kluge (1991) moved the genera Sanzinia and Acrantophis into Boa, based on a phylogeny derived from morphological characters. However, it has since been shown that the Malagasy boids and Boa constrictor do not form a monophyletic group, and the lumping of Sanzinia, Acrantophis and Boa was, therefore, an error. These snakes are therefore correctly represented in their own genera: Sanzinia and Acrantophis.
To add further to the naming confusion, many species of snake in the family Boidae are known colloquially as "boas". Also, more than a few subspecies of B. constrictor are recognized, several of which have distinct common names.
^Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN0-8069-6460-X.
^McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN1-893777-00-6 (series). ISBN1-893777-01-4 (volume).
^Kluge AG. 1991. Boine Snake Phylogeny and Research Cycles. Misc. Pub. Museum of Zoology, Univ. of Michigan No. 178. 58 pp.
^Vences, Miguel; Glaw, F.; Kosuch, J.; Boehme, W.; Veith, M. (2001). "Phylogeny of South American and Malagasy boine snakes: Molecular evidence for the validity of Sanzinia and Acrantophis and biogeographic implications". Copeia. 2001 (4): 1151-1154. doi:10.1643/0045-8511(2001)001[1151:posaam]2.0.co;2.
^Reynolds, R.G.; Niemiller, M.L.; Revell, L.J. (2014). "Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling". Molecular Phylogenetics and Evolution. 71: 201-213. doi:10.1016/j.ympev.2013.11.011. PMID24315866.
Kluge AG. 1991. Boine Snake Phylogeny and Research Cycles. Misc. Pub. Museum of Zoology, Univ. of Michigan No. 178. 58 pp. PDF at University of Michigan Library. Accessed 11 July 2008.
Vences M, Glaw F, Kosuch J, Böhme W, Veith M. 2001. Phylogeny of South American and Malagasy Boine Snakes: Molecular Evidence for the Validity of Sanzinia and Acrantophis and Biogeographic Implications. Copeia No 4. p. 1151-1154. PDF at Miguel Vences. Accessed 29 August 2008.
Vences M, Glaw F. 2003. Phylogeography, systematics and conservation status of boid snakes from Madagascar (Sanzinia and Acrantophis). Salamandra, Reinbach, 39(3/4): p. 181-206. PDF at Miguel Vences. Accessed 29 August 2008.