This name is a synonym of Hymenoxys richardsonii var. floribunda (A.Gray) K.F.Parker.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 678340D1-52BE-4CD0-981F-77785F22B53B).
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 Hymenoxys floribunda in version 1 of The Plant List.