⚠ Version 1 of The Plant List has been superseded.
This name is in version 1.1 of The Plant List, record tro-50120883, with some changes.
This name is a synonym of Rhododendron maximum f. purpureum (Pursh) Fernald.
The record derives from Tropicos which reports it as a synonym (record 50120883) with original publication details: Fl. Amer. Sept. 1: 297 297 1814.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:219496-2.