This name is a synonym of Agoseris heterophylla (Nutt.) Greene.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record E5B78D86-0551-4A9A-A1E9-E9C8A5BA17CE).
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 Troximon heterophyllum in version 1 of The Plant List.