This name is a synonym of Mila caespitosa Britton & Rose.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 5102143) with original publication details: Ashingtonia 3(3–4): 62 1978.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:875325-1.
This name was in version 1 of The Plant List, record tro-5102143, and has not been changed.