Don't know but you may wish to look at the lobelias. It has that sort of look to it.

FataMorgana

I thought maybe one of the skullcaps, Scutellaria genus? Flower is reminiscent.

Maybe Lobelia siphilitica, Great Blue Lobelia?

Not L siphilitica.

Lobelias have alternate leaf arrangement. Plant in question has opposite leaves.

Salvia hispanica ????

Nice find, floral. I worked through all of the US native and non-native Salvia species, and Salvia hispanica is the only one that fit. Thank you, all, for your help.