Thank you, Jolana, greene and plantladylin,
It seems as if the names Oxalis vulcanicola Burgundy and Oxalis vulcanicola Zinfandel are interchangeable, and at ATP the plant is listed as Volcanic Sorrel (Oxalis spiralis subsp. vulcanicola 'Zinfandel') , Plant ID#168015, and that's what I'll go with. You've steered me in the right direction. Thanks again.