Thanks again to Earl Blackstock for submitting photographs of some of the native azaleas of the eastern USA. The first photograph — Rhododendron austrinum — was taken by Earl’s granddaughter Libby on April 20. The other image, Rhododendron flammeum, was taken in the past few days. A couple years ago, Earl submitted a photograph of a related azalea, Rhododendron periclymenoides.
Both of today’s azaleas and the one submitted a couple years ago are deciduous azaleas and hence members of the section Pentanthera (one of eight sections within the genus Rhododendron). Rhododendron austrinum, or the Florida azalea, is native to Alabama, Florida, Georgia and Mississippi. Oconee azalea (Rhododendron flammeum) is found in one fewer state and slightly further northeast: Alabama, Georgia and South Carolina.
The late Hal Bruce, former plant taxonomist at Winterthur Gardens, wrote extensively about deciduous azaleas in this article for the Quarterly Bulletin of the American Rhododendron Society: “Deciduous Azaleas at Winterthur“. For more information, and particularly photographs, you’ll also want to visit David Royster’s Virtual Rhododendron Garden (see: Native & Deciduous Azaleas of the Piedmont). The photographs on Royster’s site also show part of the range of flower colour variation within these species. For growing information and more, Earl has suggested Henning’s Rhododendron and Azalea Pages.