İn a study the aerial parts of Salvia cryptantha was found to have 50 micg/g Salvinorin A, and a much higher amount of Salvinorin B. İt must have a special chemistry that makes it orally active... To my knowledge this is the first success in experiencing Salvinorin A with a species other than divinorum. This species is endemic to Turkey and is very common and abundant to say the least.
Another species growing in the same area where İ harvest cryptantha is S. verticillata, found to have a slightly less amount of S A than cryptantha, and is a relative of S. divinorum. Cross breeding with divinorum might be possible. İ only experimented once with this species, by quidding, and I felt subtle Salvinorin A effects, and the feeling was indeed more similar to divinorum.
All the data in this entire thread comes from a single study which measured the amount of Salvinorin A in the entire aerial parts of various Salvia species from Turkey. İ'd bet if you just measured the leaves or parts that have dense trichomes, the amounts would turn out quite higher.