I have this one [called "MARWIN Gardens"], haven't seen any flowers yet. Maybe it will bloom this winter? Parentage is unknown, though S. wagneriana has been implicated. I would definitely guess S. karwinskii, as well. I'm not sure that S. involucrata has been implicated, but Kathy at Cabrillo might know? Kermit has it on his site now, see link below.

More photos here:
http://taste.ecrater.com/p/3290548/salvia-marwin-gardens-11-seeds-giant

Here is a link that might be useful: Salvia x Marwin Gardens

No definitive info - just hearsay available from most sources. We've grown it for two plus years now as 'Marwin Gardens'. It is similar to wagneriana in floral characteristics, but by no means identical. The plant habit is different as well - more compact, larger, rounder leaves of a very different color and veination and MUCH slower growing. It acts like a pentaploid.

We grew out some seeds from it and they are all identical, not what one would expect from a hybrid. The fact that it sets seed at all flies in the face of claims that it is a hybrid.

I'm uploading early bloom pictures to my Flickr site. Give it a bit as is currently uploading. If you don't know the site, just send me email.

Nice, densely branched and leaved pink flowered Winter Salvia. That's what I'd call it. Very nice.

The foliage looks a lot more like wagneriana or involucrata to me, and the flower spike looks more like karwinskii in the photos I've seen so far.

I have 'Marwin Gardens' grown from seed and my foliage is more
karwinskii then wagneriana or involucrata, I just query the earlier question about hybrids setting seeds, on some salvias
they do and some they dont,I have a salvia African hybrid that
the foliage resembles namaensis and the flowers scabra it sets
seeds and I have sown them and thus far the foliage resembles
the plant so diviation thus far,the biggest hybrid seed setter
I know has to be the macrophylla x sagittata the foliage
is sagittata and the flowers macrophylla, this baby is not
shy in setting seeds just like the macrophylla so some hybrids set and some dont I guess, the mystery of the salvia:)