מערכת יחסים: התאמה

Natrix natrix (sensu lato) has been split twice. First Pokrant et al., 2016 split off Natrix natrix ssp. astreptophora (snakes west of the Pyrenees) as Natrix astreptophora

Then Kindler et al., 2017 split off snakes west of the Rhine as Natrix helvetica, specitically:
Natrix natrix ssp. helvetica
Natrix natrix ssp. cetti
Natrix natrix ssp. lanzai
Natrix natrix ssp. sicula
Natrix natrix ssp. corsa

leaving Natrix natrix sensu stricto (east of the Rhine) as:
Natrix natrix ssp. calabra
Natrix natrix ssp. cypriaca
Natrix natrix ssp. fusca
Natrix natrix ssp. gotlandica
Natrix natrix ssp. natrix
Natrix natrix ssp. persa
Natrix natrix ssp. schweizeri
Natrix natrix ssp. scutata
Natrix natrix ssp. syriaca