Flame Azalea (Rhododendron calendulaceum)

Flame Azalea (Rhododendron calendulaceum)

If the plant kingdom had the ability to hold their own beauty contests I think it would be safe to say that the Flame Azalea (Rhododendron calendulaceum) would be a perennial powerhouse pick to take home the crown each and every year.  It's hard enough to compete with the other azaleas and rhododendrons within the Ericaceae family but the brilliant and unique flame orange blooms of this species really sets it apart from the rest.

Flame Azalea (Rhododendron calendulaceum)

Ohio is home to four indigenous species of Rhododendron : Rosebay (R. maximum); Rose Azalea (R. prinophyllum); Pinxter-flower (R. periclymenoides) and the featured Flame Azalea (R. calendulaceum).  All four are state-listed and quite rare in Ohio with the flame azalea being the rarest and currently listed as endangered.  Fathom that our most gorgeous and unsurpassed rhododendron species would also be our most uncommon.  Even in pre-settlement times these plants were infrequent and scattered in local populations throughout south-central Ohio, only to be dug up and transplanted by early pioneers and settlers for their homesteads and gardens; a practice still used today.  I can't say that I blame them for wanting to bring the beauty and 'fire' home with them to enjoy and cherish.

Rhododendron calendulaceum distribution map courtesy BONAP

Observing the range of the flame azalea reveals its southern Appalachian distribution from Alabama and Georgia, up through the Cumberland plateau and onto the Allegheny plateau in Ohio and West Virginia before suddenly ceasing before reaching into New England.  Ohio's outlier part of the range is a direct result of the antiquated and pre-glacial Teay's River flowing northwest from Virginia, though West Virginia and on into our state.  This long extinct river was a super highway for southern and coastal plain flora to migrate up into current day southern and southeastern Ohio; such as the flame azalea.

Flame Azalea (Rhododendron calendulaceum)

The scientific epithet calendulaceum translates to 'like a calendula', which is a genus of vascular plants with similarly colored flowers native to Macaronesia and the Mediterranean region.  The common name of flame azalea actually recognizes the resemblance of the shrubs swollen, unopened flower buds to the flame of a candle.  It's just as easy to assume it also refers to the scintillating orange color of the flowers.

Flame Azalea (Rhododendron calendulaceum)

Unlike the evergreen and leathery leaves of the later-blooming rosebay rhododendron, the flame azalea as well as the other two pink taxa have deciduous leaves.  Without such obvious and conspicuous leaves it can be pretty difficult to notice and locate these deciduous azaleas when not in their blatantly obvious flower-mode.  I can only imagine what was going through famed French botanist Andre Michaux's mind when he first came across this striking shrub back in the late 1700's in the southeastern United States.  Seeing large patches and colonies of these in full, glorious bloom must be something an individual is not likely to forget in their lifetime.

Flame Azalea (Rhododendron calendulaceum)

It's not too uncommon to see these remarkable shrubs planted and used in cultivation throughout the acidic soiled regions of Ohio.  It has become an increasingly difficult thing to determine the validity and origin of newly discovered populations of this species considering their ornamental value and popularity.  I'd find it hard to believe that there would be any natural populations left undiscovered in Ohio.  Being so pronounced and meretricious during a few weeks in late spring is an easy way to get noticed by even the most casual observer.

I'm very thankful to have come across the opportunity to see and photograph this flawless and superlative plant and mark it off my life species list.  The only thing better than the thrill of the hunt is the ecstasy of discovery!  I hope you enjoyed this post but now it's time to pack up and head down to Shawnee state forest for Flora-Quest 2012!  I can't wait for what adventures and experiences this year holds and will be sure to share it all upon my return.