This name is a synonym of Erioneuron pilosum (Buckley) Nash.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 25523176) with original publication details: Revista Argent. Agron. 4(4): 251, f. 2A–B 1937.
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 Tridens pilosus in version 1 of The Plant List.