Identifying the East Coast Native Azaleas

Orange to Red Group

East Coast Native Azaleas   -   THE ORANGE GROUP
The "orange group" of the native azaleas includes five main species: Rhododendron austrinum, R. calendulaceum, R. cumberlandense, R. flammeum, and R. prunifolium. Flowers in this group can range from yellow, through orange, to deep red.

Some of these plants are easy to distinuish because of fragrance or the season of bloom. Others, however, require close inspection to help to distinguish between the species. Use the chart below to help discriminate among these five orange group native azalea species found in the eastern United States.

1. Is the flower tube longer than the lobes of the corolla?
YES 2. Do the flowers bloom in early spring as the leaves are expanding?
YES 3. Are the flowers fragrant?
4. Is the flower sticky due to the presence of "glandular hairs"? The flower might be yellow through deep orange, and the tube is often tinged with rose red. However, there should be no blotch.
  • Yes The flower is probably R. austrinum
  • No. The plant may be a hybrid.
5. Is the flower bright scarlet, red, or orange with a large orange blotch? The corolla usually does not have any glands on the outside so it is not usually sticky.
  • Yes The flower is probably R. flammeum
  • No. The plant may be a hybrid.
6. Are the flowers orange or scarlet and does the plant bloom very late in July and August? Next year's flower buds are usually formed already.
NO 7. Do the undersides of the leaves have a waxy white or bluish color?
8. Are the flowers orange or red and bloom long after the foliage has fully expanded?
  • Yes The flower is probably R. cumberlandense
  • No. The plant may be R. calendulaceum or possibly a hybrid.
9. Are the flowers yellow to orange-red and open with, or shortly after, the foliage expands?
  • Yes The flower is probably R. calendulaceum
  • No. The plant may be R. cumberlandense or possibly a hybrid.

Copyright © 2001 Donald W. Hyatt