1 Centavo Fuerte

The provincial banks of Argentina's interior operated in a legal grey zone throughout the 1870s. Banco de San Juan was one of several institutions issuing fractional notes — centavos fuertes — that filled a chronic shortage of small-denomination specie, particularly silver coin, which routinely drained out of circulation through hoarding and cross-border trade. A 1-centavo note is about as low as paper money gets anywhere in the world, which tells you something about how severe that shortage was in Tucumán.

The PS prefix in the Pick reference places this firmly in the speculative/private bank category, and survival rates for these fractional provincials are poor — the notes were treated as disposable tokens rather than stored currency.