I am pretty sure it is a true Salvia guaranitica, as much as `Black and Blue' is. I am growing at least four 12 - 14" pots of these two along with the old-fashioned form (anise-scented), `Blue Ensign', the Van Remsen form, and `Purple Majesty'. B&B and AS are very similar to one another, with AS more robust. BE is like Anise scented but more vigorous. Van Remsen is bigger yet, but not like PM. These last two do not have stolons (runners), and Van Remsen has few tubers and PM none.

S. guaranitica is found in the wild in southestern Brazil to Argentina. I am pretty sure the S. ambigens form is from Brazil. AS was brought into the USA by Charles Cresson of Philadelphia, and he got it from Juan Patricio OÂFarrell, who collected seed in river basin, Paraua. He made a selection from a population with variable colors.

Charles received seed in 1987, germinated them in the summer of 1987, and selected the lightest of 2 seedlings from 4 seeds. The name was published in the RHS Journal, Letters from Members The Garden, Sept 1990: A New Salvia Argentina Skies.

Early in the 20th century, S. ambigens and S. melanocalyx were merged into S. guaranitica. A recent paper on the DNA of South American sages states that many from Argentina are polyploidal. Also, both S. mexicana and S. greggii are also found in the wild with mixed populations where the ramge of colors goes from clear green calyxes with light flowers to plants with dark pigmented calyxes and dark flowers.

Thanks, Richard, for the info.

Very interesting....if a bit confusing!

Robin.

the american horticultural society "encyclopedia of garden plants" does list "argentine skies" under s. guarantica. "black potatoes" is a perfect description! this plant is a bit of a thug when grown in good soil - i've been able to keep it at bay in unamended clay.

Well, folks, you successfully sent a chill up my back! I garden beachside in Central FL. Down here, well amended sand can make monsters of even well mannered plants! I purchased two Argentine Skies 6 weeks ago from a vendor at a Master Gardener plant sale. They are planted in a new small bed with a key lime tree, daylilies and miniature roses. Previously, heliconias dominated the space--true invasives if there ever was! The Argentine Skies have really taken off! I just came in from lift them and potting them in 5 gallon pots--not a moment too soon. I think they were eying that little key lime tree while I dug!