Synopsis of the New Section Nothoscordum sect. Gracilia (Amaryllidaceae)

Nothoscordum Kunth is a New World genus distributed from the United States into South America, where its highest diversity is found in Argentina, Chile, Bolivia, Brazil, Peru, and Uruguay. The circumscription of the genus, as well as the taxa included, has been a source of confusion. The large number of taxa described, combined with incomplete keys to species and the difficulty or impossibility of contrasting published descriptions with type material, and with illustrations when available, has created a deep-rooted taxonomic confusion. The convergence of this challenging scenario with the difficulty of finding diagnostic morphological characters has transformed species circumscription into a formidable task. As a first step toward a comprehensive revision of Nothoscordum, a description and nomenclatural account of Nothoscordum sect. Gracilia (Aiton) Sassone, S. Arroyo & P. Moroni (including the cosmopolitan weed N. gracile (Aiton) Stearn) is addressed. Following an extensive review of specimens covering the entire distributional range of the section, a list of names and their types is provided here. It also entails the lectotypification of 10 names, alongside the designation of eight neotypes and one epitype. Fifteen names are synonymized. Additionally, six doubtful species are discussed and one excluded.