Rhododendron calendulaceum

The Beauty of the Flame Azalea

The following two images are taken near Roan Mountain at Engine Gap and Jane Bald. The photographs should be easily recognized by those who frequent the area since these two native azaleas are well known, not only for their distinctive qualities but also for their settings. The contrast of the brilliant colors of R. calendulaceum against the Blue Ridge Mountains in this region makes the display very spectacular.

Compact Yellow near Engine Gap

"Molten Lava" near Jane Bald

Variations in Flower Color

The flowers of R. calendulaceum range from yellow, yellowish-orange, orange, to red or scarlet with an orange blotch. Some forms may open as yellow or orange, and will then deepen in color as they age to orangre-red or even scarlet. The terminal inflorescence can contain 5 to 8 flowers, with the individual corolla varying from 2.5-4 cm. long, to 3-5 cm. across.

Orange near Engine Gap

Red near Wayah Bald
Compact Yelow near Engine Gap
"Molten Lava" at Jane Bald

Distinguishing Characteristics

  • The flowers open along with the leaves, or shortly thereafter.
  • The corolla is openly funnel shaped, and the tube is about the same length as the width of the petals, or slightly shorter.
  • The flowers have a prominant blotch but they are not fragrant.
  • The undersides of the leaves are pubescent, but not waxy white.
  • The plant is tetraploid, thus having twice the number of chromosomes as most native azalea species.

Plant Habit

This species is usually a well branched deciduous shrub, upright, with spreading branches about 1.5 to 3 meters high. In open woodlands, the plant can occasionally reach 4 meters or more, but is more open and arching.

Natural Bloom Time

This species can have quite a variation in bloom time. On Roan Mountain, for instance, clones of R. calendulaceum can start blooming in early June, while others may not open until July. Peak bloom in that region is usually around June 21st, the longest day of the year.