The record derives from TICA
(data supplied on )
which reports it as a synonym (record
F3EA81C1-13E7-49B3-B5B2-B4A181C4E5F7) with original publication details: "C.F. von Ledebour, Fl. Ross. 2. 1846" 838 1846.
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 Youngia pygmaea in version 1 of The Plant List.