1	"Rhizome tuberous"	"Nepeta tuberosa"
1	"Roots not as above"	2
2	"Leaves linear-lanceolate; flowers blue or yellow"	"Nepeta nervosa"
2	"Characters not all as above ."	3
3	"Corolla 12–17 mm long"	"Nepeta grandiflora"
3	"Corolla less than 12 mm long ."	4
4	"Leaves mostly more than 3 cm long ."	"Nepeta cataria"
4	"Leaves to 3 cm long"	5
5	"Leaves ovate, base distinctly cordate"	"Nepeta racemosa"
5	"Leaves narrowly oblong, to narrowly lanceolate, base not or slightly cordate"	"Nepeta ×faassenii"