This name is a synonym of Villadia misera (Lindl.) R.T. Clausen.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50203035) with original publication details: Edwards's Bot. Reg. Misc. 65 1838.
This name record (from Tropicos) 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 Sedum miserum in version 1 of The Plant List.