Comanthera consists of 41 species grouped in two subgenera. Both subgenera are restricted to South America and include most of the species of Eriocaulaceae used commercially as everlasting plants. Molecular and morphological phylogenies have revealed the genus and both its subgenera as monophyletic, but relationships among species have yet to be investigated. The last revision of Comanthera subg. Thysanocephalus is more than one century old, and the recognition and circumscription of taxa are still poorly understood. The present work aims, therefore, to study the taxonomy of C. subg. Thysanocephalus. Herein, descriptions of the genus and subgenus are provided along with identification keys for the subgenera and species. This taxonomic treatment proposes 17 new synonyms, excludes three taxa, and designates four lectotypes. One new species, Comanthera dimera, is described and illustrated, one variety is elevated to species status, C. angustifolia, and one species is resurrected with a new combination, C. tricostata. Nine species are accepted with no sub-specific ranks, yielding a total of 35 species in the genus Comanthera. Comments on phenology, habitat, and distribution, along with diagnoses, taxonomic notes, and distribution maps are provided.