Prodromus of a fern flora of Bolivia. XLII. Update I. Author Kessler, Michael Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, CH- 8008 Zurich, Switzerland. Author Smith, Alan R. University Herbarium, 1001 Valley Life Sciences Bldg. # 2465, University of California, Berkeley, CA 94720 - 2465. Author Øllgaard, Benjamin Department of Biology - Ecoinformatics and Biodiversity, Ny Munkegade 116, building 1137, 8000 Aarhus C, Denmark. Author Matos, Fernando B. Centro de Referência em Informação Ambiental (CRIA), Rua João Carlos do Amaral 500, 13070 - 111, Campinas, SP, Brasil. Author Moran, Robbin C. New York Botanical Garden, 2900 Southern Blvd., Bronx, New York, 10458 - 5126, USA. text Phytotaxa 2023 2023-12-20 630 3 183 210 https://phytotaxa.mapress.com/pt/article/download/phytotaxa.630.3.2/51376 journal article 10.11646/phytotaxa.630.3.2 1179-3163 10409920 Serpocaulon A recent monograph of Serpocaulon by Sanín et al . (2023) necessitates some revision of the treatment of that genus for Bolivia . The following species, some new records, some as a result of recircumscription of previously recognized species, need to be added to the treatment of Smith et al . (2018). A newly named species is S. australe , which now includes the specimens heretofore called Serpocaulon gilliesii by Smith et al . (2018). In fact, the name S. gilliesii is now treated as a synonym of S. lasiopus , so that it applies to a different species ( Sanín et al . 2019b ; Sanín et al . 2023 ). Serpocaulon rex , previously known only from southern Brazil , is now known from several sites in Bolivia , and S. dasypleuron and S. wagneri , both fairly widespread in South America, are now considered to occur in Bolivia as a result of reidentifications of existing material. Several species recognized by Smith et al . (2018) are now excluded from Bolivia : S. silvulae , is now placed into synonymy under a previously recognized species, S. crystalloneuron . Specimens previously called S. caceresii for Bolivia are now understood to all be S. articulatum ; the former species has been wrongly interpreted ( Sanín et al . 2021 ), and collections previously determined as S. caceresii generally represent either S. articulatum or S. psychotrium ( Sanín et al . 2023 ) , a species known only from Venezuela and Colombia to Peru , but possibly to be found in Bolivia . Two additional species recognized by Smith et al . (2018), S. latipes and S. ptilorhizon , are no longer known to occur in Bolivia ; specimens called this for Bolivia are assignable to other species, namely S. intricatum for the former, and either S. funckii or S. subandinum for the latter. As a result of these changes, the number of species known from Bolivia has increased by 3 (6 additions, 3 deletions) to 24. The particulars for all taxa are summarized following a new key for all species in the genus. For a full accounting of the taxonomy, synonymy, and ranges of species of Serpocaulon , the monograph by Sanín et al. (2023) should be consulted. Images of specimens indicated by an asterisk are available on the Pteridoportal (www.pteridoportal.org).