Two species of Prestonia are described: P. lauta (endemic to Colombia) is characterized by its tomentulose stems, subterminal (rarely axillary) inflorescences, elongated pedicels, and corolla without free corona lobes, and P. occultata (restricted to Ecuador and Peru) is recognized by its densely to sparsely adpressed puberulent stems, terminal to subterminal inflorescences, small sepals, inconspicuous free corona lobes, and 5-lobed ovary. Terminal or subterminal inflorescences are rare in Prestonia and restricted to six species (including the two here described). Prestonia now comprises 60 neotropical species. We provide illustrations, distribution map, and a key to the species of Prestonia with terminal or subterminal inflorescences.