This name is a synonym of Brickellia diffusa (Vahl) A.Gray.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 6643CD01-2696-4DBD-ACAB-FFCD6FB45C31) with original publication details: Encycl. Suppl. 2: 329. 1811. 329 1811.
This name record (from TICA) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Chondrilla rhombifolia in version 1 of The Plant List.