The present study concerns Brazilian specimens that Carl Martius sent to Luigi Colla in 1827 and from which Colla described 24 new species in volume III of Herbarium Pedemontanum in 1835. The original material examined by Colla (now held at TO) was found and compared with duplicates held elsewhere. Material was located for all but two of the taxa described by Colla. Eighteen hitherto unresolved species names are here clarified, along with 23 new synonymies, 20 proposed lectotypifications and one epitypification, and three new combinations. Based on the collecting localities and comparison with specimens at Herbarium Martii at BR and elsewhere, at least 22 of the specimens distributed by Martius can be confirmed as collections made by Prince Maximilian zu Wied.