This name is a synonym of Parthenium argentatum A.Gray.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record A272549E-BF54-45D7-9F9C-5FA1B5D54BFA).
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 Parthenium argentatum in version 1 of The Plant List.