A synopsis of Carex subgenus Psyllophorae, sect. Junciformes (Cyperaceae) in South America

Abstract This is the second study of a series of thorough studies into the taxonomy and systematics of Carex in South America. Here, we present the systematic placement, taxonomic account, formal typifications, and summarized distributions for the 31 accepted South America species of Carex subg. Psyllophorae, all belonging to sect. Junciformes. We have conducted an exhaustive revision of literature, more than 400 specimens from 32 South and North American and European herbaria have been studied, and a Sanger phylogenetic study with four DNA regions and morphometric analyses for the C. phalaroides group have been performed. We present an enlarged phylogenetic study where sect. Junciformes sampling has increased by 11 species regarding previous studies, only lacking four species of the group (C. herba-alpacae, C. moorei, C. nelmesiana, and C. transandina). South American species of sect. Junciformes are grouped into four major lineages: C. camptoglochin Clade, Aciculares Clade (South America and Australia–New Zealand), C. phalaroides group, and Junciformes Clade. We have resolved the C. phalaroides complex into six independent species with a clear geographic structure. We successfully unravelled the systematic placement of three species included here for the first time (C. boelckeiana, C. reicheana, and C. manuelbarrosii). An identification key is provided for the studied species. We propose 30 new typifications, and four new species are described (C. herba-alpacae, C. manuelbarrosii, C. melliza, and C. via-montana).