Introduction The genus Cleistes Rich. ex Lindl. (Orchidaceae: Vanilloideae: Pogoniinae) comprises about 30 species distributed throughout Central and South America. According to Cameron & Chase (1999) and Pansarin et al. (unpubl. res.), Cleistes is paraphyletic. The North American species C. divaricata and C. bifaria are closer to the North American Pogoniinae genera Isotria and Pogonia than to the Central and South American Cleistes. The Central and South American species of Cleistes form a natural group (Cameron & Chase 1999). They are found in several habitats including disturbed areas on road margins, "campo limpo" (open grasslands), "campo sujo" (grassland with shrubs), "cerrado" (wooded savanna), "vereda" vegetation (wet grassland) in the Central Plateau, "restinga" (open seashore vegetation on sandy soil), sandy rocky soils or among rocks in "campos rupestres" (vegetation of rocky outcrops), marshy areas and "campos de altitude" (high mountain grasslands). This new species, Cleistes pusilla, was found while preparing a taxonomic revision of the genus Cleistes.