This name is a synonym of Antennaria howellii subsp. petaloidea R.J.Bayer.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 062D6587-EF6E-4DF1-8EF7-D974FD98477B).
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 Antennaria petaloidea in version 1 of The Plant List.