Abstract
Stachytarpheta kriegeriana, a new species of Verbenaceae exclusively known from the type specimens collected at the municipality of Monte Alto, São Paulo state, is here described and illustrated. The new species is similar to S. hirsutissima due to its densely hirsute indumentum, but can be differentiated by its leaves and bracts morphology, and by the bract/calyx ratio. Stachytarpheta kriegeriana belongs to the informal group “Cayennensis” due to its inflorescences up to 6 mm wide and its calyx embedded in the rachis excavations. An identification key for the species within the “Cayennensis” group is provided, together with a map highlighting the collection site, habitat information, illustration, and conservation assessment for the new species.