I grow Lemon Verbena (actual culinary/medicinal herb) and when rubbed it produces a better lemony smell than...well...lemons! If only I could get that smell into some bud!
What you want is lemon thai.
The original came from dutch flowers, a few other seed companies have offerings that are based on that line...
Well I've got a sweet lemon "Chrystal" pheno and a sharp lemon sativa running now.
That lemon is a special breed allright, looks a bit like what Cannacopia used.
[Cannacopia's plant btw]