Premise: Rhododendron catawbiense, with common names Catawba rosebay, Catawba rhododendron, mountain rosebay, purple ivy, purple laurel, purple rhododendron, red laurel, rosebay, rosebay laurel, is a species of "Rhododendron" native to the eastern United States, growing mainly in the southern Appalachian Mountains from Virginia south to northern Alabama.
Hypothesis: Purple ivy is not Rhododendron catawbiense.