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. var. speciosa

Treated here as a naturally occurring variety of Rhododendron calendulaceum (Michx.) Torr. Tall growing deciduous azalea with funnel-shaped red flowers with yellow spots.  To 2m.  [RHSD, Hortus].  

Horticultural & Botanical History

Paxton's Dictionary describes Azalea speciosa as an American species and lists several varieties.  ‘[Azalea speciosa is] a rich rose with crimson blotch and spots; very showy, flowers large.  The plant was seven feet by five.’  [FC p.136/1848].  ‘[Azalea speciosa aurantica] is a native of Carolina, has been long cultivated in England, and is hardy enough to bear our winters uninjured.’  [LBC no.1255/1828].

History at Camden Park

Only listed in the 1845 catalogue.


The identity of Macarthur’s Azalea speciosa is in some doubt because Azalea speciosa and Rhododendron speciosum are confused names having been variously applied to Rhododendron ponticum L., a European species, and Rhododendron indicum Sweet, a Japanese species, as well as Rhododendron calendulaceum (Michx.) TorrHowever Rhododendron calendulaceum (Michx.) Torr. var. speciosa is the most likely identification.

Published Jun 08, 2009 - 01:05 PM | Last updated Sep 11, 2011 - 04:44 PM

Figured is a single azalea with brilliant orange flowers.  Loddiges Botanical Cabinet no.1255, 1828.

Rhododendron calendulaceum (Michx.) Torr. var. speciosa | LBC no.1255/1828 as Azalea speciosa | RBGS


Family Ericaceae
Region of origin

Eastern USA

  • Azalea speciosa Willd.
  • Rhododendron speciosum (Willd.) Sweet
  • Azalea aurantiaca Dietr.


Common Name

Flame azalea

Name in the Camden Park Record

Azalea speciosa 


Confidence level medium