Naja is a genus of venomous elapid snakes known as cobras. Several other genera include species commonly called cobras (for example the ring-necked spitting cobra and the king cobra), but members of the genus Naja are the most widespread and the most widely recognized as "true" cobras. Various species occur in regions throughout Africa, Southwest Asia, South Asia, and Southeast Asia. Until recently, the genus Naja had 20 to 22 species, but it has undergone several taxonomic revisions in recent years, so sources vary greatly. Wide support exists, though, for a 2009 revision that synonymised the genera Boulengerina and Paranaja with Naja. According to that revision, the genus Naja now includes 38 species.