The preparation of treatments of Dilleniaceae for the Flora of Colombia and Flora of Ecuador projects required a literature survey, visits to herbaria, and the analysis of types and general collections found on the Internet. The results indicate the need to lectotypify several species of Dilleniaceae described by the Colombian botanist José Jerónimo Triana. These taxa are based on specimens collected during Triana's participation in the Colombian Chorographic Commission (“Comisión Corográfica”) from 1851 to 1857, under the supervision of Agustín [Giovanni Battista Agostino] Codazzi. Lectotypes for the following six species are proposed herein: Davilla densiflora, Ricaurtea congestiflora, Ricaurtea nitida, Tetracera castaneifolia, Tetracera hydrophila, and Tetracera sessiliflora.