Colin Mills, compiler of the Hortus Camdenensis, died in late November 2012 after a short illness. As he always considered the Hortus his legacy, it is his family's intention to keep the site running in perpetuity. It will not, however, be updated in the near future.

Rhododendron calendulaceum (Michx.) Torr.

The species is a robust, deciduous azalea with lax trusses of funnel-shaped, bright orange to scarlet flowers, to 5cm across, usually opening with the leaves or just after they emerge, in late spring or early summer.  One of the most vividly coloured of the wild azaleas.  To 2.5m.  [RHSE, Hortus, Hilliers'].

Horticultural & Botanical History

‘The present variety of this species seems to be universally acknowledged the most ornamental shrubs in North America; where it is found on the banks of rivers and the slopes of hills in Georgia and Carolina.’  [BR f.145/1816].  ‘Found in 1774, by our late venerable friend William Bartrum, who in his travels gives this most glowing description of its beauty.  “The clusters of the blossoms cover the shrubs in such incredible profusion on the hill sides, that suddenly opening to view from deep shades, I was alarmed by the apprehension of the hill being set on fire.”  He calls it certainly the most gay and brilliant flowering shrubs yet known.’  [LBC no.1324/1829].  Introduced to Britain in 1806.  [JD].

History at Camden Park

Listed in all published catalogues [T.75/1843].


Rhododendron [Azalea] calendulaceum Hook. & Arn. (1839) = Rhododendron occidentale A.Gray and is unlikely to be Macarthur’s plant.

Published Jun 08, 2009 - 10:35 AM | Last updated Sep 11, 2011 - 04:45 PM

Figured is a single azalea with bright yellow flowers.  Loddiges Botanical Cabinet no.1324, 1828.

Rhododendron calendulaceum (Michx.) Torr. | LBC no.1324/1828 as Azalea calendulacea | HAAB


Family Ericaceae
Region of origin

Eastern USA

  • Azalea calendulacea Michx.


Common Name

Flame azalea

Name in the Camden Park Record

Azalea calendulacea 


Confidence level high