Adiantum forzzanum and A. matogrossense (Pteridaceae) are described as new from west-central Brazil. Adiantum forzzanum resembles A. lorentzii, and A. matogrossense resembles A. ruizianum and they were previously identified as such. Both species, however, can be distinguished by their yellow-farinose indusia and the presence of glands that produce farina (whitish or cream-colored, or yellowish) on the lamina abaxially. These two new species are described, illustrated, and discussed, and a key to distinguishing all other closely related species of the A. raddianum group in the Neotropics is also presented. This contribution adds two more endemic species of Adiantum to the flora of Brazil and is part of our ongoing effort to improve the circumscription of the A. raddianum group.