Physaria okanensis Al-Shehbaz & Prina (Brassicaceae), a new species from Catamarca, Argentina, is described and illustrated. It is distinguished from the five other South American species of Physaria (Nuttall) A. Gray by its densely pulvinate habit and few-flowered scapes. It resembles the non-pulvinate, often non-scapose P. pygmaea O'Kane & Al-Shehbaz, but also differs by having longer petals and larger, orbicular (vs. ovoid) fruits. The IUCN status of the new species is determined as Data Deficient (DD).