This name is a synonym of Townsendia exscapa (Richardson) Porter.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 43B2A70A-28A8-410A-A302-AAFE5C5C756C) with original publication details: 32 1823.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:328071-2.
This name was in version 1 of The Plant List, record gcc-107828.