This name is a synonym of Lactuca tatarica (L.) C.A.Mey..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 9325D43B-C58C-44EA-8BC6-0400993D3138).
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 Lactuca pulchella in version 1 of The Plant List.