The genus Rhododendron is grouped into the heath family, Ericaceae which contains many acid soil loving species. The species are native to temperate areas of the Northern Hemisphere but are most abundant in the Himalayas and other mountains of Asia. This plant is a cultivar of the species, R. catawbiense which is a native of southeastern United States with a range extending from Virginia to Georgia and Alabama. It was introduced into Europe in 1799 by John Fraser, a Chelsea, England nurseryman who was a leading importer of North American plants. This species is found in the ancestry of many of the modern Rhododendron hybrids. 'Lee's Dark Purple' is an early R. catawbiense cultivar introduced before 1851 and is counted among the "ironclads."
Rhododendron was named and classified by Linnaeus who named it from the Greek for rose tree. This genus also contains shrubs commonly called azaleas within its 800 Rhododendron species and thousands of hybrids.