The family Boidae consists of the nonvenomous snakes commonly called boas and consists of 43 species. The genus "Charina" consists of two species, both of which are found in North America. "Charina bottae" is sometimes also known as the coastal rubber boa or the northern rubber boa and is not to be confused with the southern rubber boa ("Charina umbratica"). There is debate on whether the southern rubber boa should be a separate species or a subspecies ("Charina bottae umbratica"). A study published in 2001 concluded there is enough evidence to indicate that the proposed independent species, "Charina umbratica", is a separate species based on its geologically separate genetic nature and morphological differences.