Picumnus is a large genus of piculets. With a total length of 8–10 cm (3–4 in), they are among the smallest birds in the woodpecker family. Species limits in this genus are doubtful, and the rate of interbreeding is "inordinately high" (Remsen et al. 2007). As defined by Winkler and Christie (2002), it contains the 27 species listed below, all from the Neotropics except the speckled piculet, which is Asian (and sometimes placed in a monotypic genus, Vivia).