Bulbs deep, Rhizomes surface. Which ones do you have?

Dutch Iris and Iris reticulata have true bulbs--they look vaguely like shallots--and should be buried 2-3 times their diameter deep.
Bearded Iris and Louisiana Iris have rhizomes--they look vaguely like ginger root--which should be just showing above ground when planted.
Spuria Iris also have rhizomes, but should be planted 3-5 cm deep.
Siberian Iris rhizomes need to be planted 7-10 cm deep.