Siberian Iris is a type of garden iris, of which there are countless "varieties" that are cultivated, with new ones added every year. The scientific name of siberian iris is "Iris sibirica," so if you were to google an image of "siberian iris" you would find many different color variations. If you wanted to get this particular variety of iris for your garden, you would have to search for this specific variety ("salamander crossing"). Often varieties go in and out of vogue, and are no longer available except from specialty nurseries or iris breeders/hobbyists. Bearded iris and roses are like this too. Where I live there is a chapter of the Iris and Daylily Society (there are even iris forums!), and every year they have a fundraiser where members dig up their "extras" and sell them at the annual sale. I've been going the last few years, and last year managed to pick up this variety.