It is important to emphasize that although morpho-species have not a valid name they’re different from undetermined species. Morpho-species were collected and compared with herbarium vouchers (then a real identification work have been made) and they include a combination of known tree species not observed in an Amazonian region (and/or unknown to the botanist in charge of the inventory) as well as new tree species. On the contrary, undetermined species were missed (or their vouchers lost) during the inventory and the unique way to identify them would be going back to the field.
In Ter Steege et al. (Science 2013), they evaluated that Amazon Basin and Guiana shield (Amazonia) harbors 16,000 tree species. Analyses were performed with data from ATDN network that comprises tree inventory plots distributed across Amazonia. Although morpho-species represent almost 15% of all ATDN species they were treated in this study as undetermined individuals and excluded from the analyses. In French Guiana we have approximately 1600 tree species with a valid name and 391 morpho-species : almost 20% of all French Guianas tree species are morpho-species. In order to integrate these morpho-species in pan-Amazonian analyses it would necessary to standardize them and improve their botanical identification.
Then it is now highly important to work on both morpho-species standardization and the description of new species to improve our knowledge on tree diversity so as to contribute to improve the quality of future pan-Amazonian analyses.