Pseudocrossidium linearifolium (Barbula subrevoluta var. linearifolia Müll. Hal.) is a new combination and status proposed for a neglected South American taxon. This distinctive moss has been known only from the type locality in the mountains around Córdoba, Argentina. It is newly reported for the moss floras of Ecuador and Bolivia. The species is described, lectotypified, illustrated and its distribution is mapped. Diagnostic characters and distinction from some closely related South American taxa, with which it may be confused, are discussed. Pseudocrossidium perrevolutum is reduced to the synonymy of P. replicatum.