Recent studies have determined that the nightsnakes in this area should be considered a distinct species, split out from Hypsiglena chlorophaea. However, the actual description of this new species has not yet occurred, so they are in a sort of taxonomical limbo for the moment.

The white nape is a feature apparently found only on this yet-to-be described species of nightsnake. However, it is not present on all individuals (such as the first one pictured above).