A recent phylogenetic study by our working group found that the foliose-macrosquamulose basidiolichen genera Cora and Corella contain at least 126 species, over 110 of them as yet undescribed. With this contribution, we begin the herculean task to formally describe these species and discuss their morphological and ecological features within the framework of their molecular phylogeny. Here, we treat four new species of Cora plus an additional new species of Dictyonema, all found in the same area in the Orinoquia region in eastern Colombia. Cora casanarensis L. Vargas, Moncada & Lücking resembles C. reticulifera but differs in the branched lobes with incised sutures and with broad, shallow concentric ridges; it grows on rock instead of soil. Cora fimbriata L. Vargas, Moncada & Lücking can be distinguished from C. casanarensis in the olive color when fresh, the absence of distinct concentric ridges, and the marginal cilia. Cora setosa L. Vargas, Moncada & Lücking is a very distinctive taxon, with a similar ecology as C. aspera but with a smaragd-green color when fresh and with broad, concentric ridges; it is also unique by forming almost circular lobes. Cora undulata L. Vargas, Moncada & Lücking is morphologically close to C. ciferrii; it differs, however, in the smaller lobes with dark olive-green color when fresh and in the saxicolous growth. Finally, Dictyonema giganteum L. Vargas, Moncada & Lücking can be separated from D. sericeum s.str. by the large, thick lobes with broad white prothallus and with abundant, white surface setae. All new species of Cora fall into only one of the two major Cora clades and are not closely related to the morphologically most similar taxa.