Nepenthesis one of the largest genera of carnivorous plants, comprising at least 160 species. These species produce highly modified pitchers that have evolved to target a greater variety of nutritional sources, including specific arthropod taxa, leaf litter, and mammal feces, than any other group of carnivorous plants (Clarke and Moran 2016). The physical environment and plant–animal interactions are key drivers of diversification within and among species, which challenges taxonomists who continue to seek effective means of applying species concepts and accurately classifying the members of the genus. In recent years, ecologists and evolutionary biologists have made significant progress in detecting drivers of diversification in Nepenthes. Advances in genetic sequencing methods are yielding new insights into recent evolutionary events within the genus. In this chapter, we review current trends and practices in the descriptive taxonomy of Nepenthes and provide recommendations to improve future work in this field. We also present an over-view of evolution within the genus, focusing on the contribution of genetic analyses to our current understanding of the major groups of species within the genus.