The Neotropics are the most species-rich area of the planet. Understanding the origin and maintenance of this diversity is an important goal of ecology and evolutionary biology. Success in this endeavor relies heavily on the past work of taxonomists who have collected specimens and produced the floras and monographs that constitute the foundation for the study of plant diversity. To illustrate this, we visualize collecting efforts through time and identify the importance of past taxonomic and collection efforts in generating the bulk of specimen data that broad-scale analyses rely on today. To demonstrate the importance of taxonomy for the study of Neotropical biodiversity, we showcase selected plant groups in which in-depth taxonomic understanding has facilitated exciting evolutionary and ecological research and highlight the teams of scientists who have built on the legacy of Alwyn Gentry, one of the most prolific taxonomists of the late 20th century. We also discuss challenges faced by taxonomists, including perceived subjectivity, difficulty in measuring impact, and the need to become more interdisciplinary. We end with potential solutions going forward, including integration of taxonomists in interdisciplinary research, advocacy for continued collection efforts, increased funding for alpha taxonomic research that is performed with increasingly replicable methodology, and explicit decolonization efforts to increase inclusivity and equity in the field of taxonomy. Acknowledging the central role of taxonomy and taxonomists is essential to accurately and completely describe Neotropical biodiversity patterns in an age of unprecedented extinction risk and conservation need.