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 282876 10.11646/phytotaxa.630.3.2 c8e39cd6-3a27-4e8d-b502-e890c64fd6bb 1179-3163 10409920 Phlegmariurus Øllgaard et al . (2018) treated the genus Phlegmariurus as comprising 26 species in Bolivia , one of which was named P. sotae (Rolleri) B.Øllg. However, I am now convinced that this species should more properly be named P. aristei . The application of the name Urostachys aristei Nessel has been uncertain due to apparent mislabeling of the lectotype in BONN (Herb. Nessel 161). In the protolog, Nessel cited two collections: “Columbien: Departement de Cundinamarca, Paramos de Gutierrez, Alt. 3290 m ( J. Aristé , 21 II 1924 , Herb. Nessel), and “Tolima, H. Kaerber 1892, Herb. Bonaparte”. Due to the species epithet, it is logical to appoint the Aristé specimen as the lectotype , also because the Kaerber specimen has so far not been located. The lectotype label (in Nessel’s handwriting) indicates “Columbien: Cundinamerica” as the locality ( Fig. 4 ). The problematic use of the name has been discussed earlier ( Øllgaard 1992 , 1994 , 2019 ). I am now convinced that the lectotype is not from Colombia , but from Argentina . Nothing I have seen from Colombia matches it, but part of an isotype of Lycopodium sotae Rolleri , in US (1420823) ( Fig. 5 ) matches the lectotype of P. aristae , including rather obvious features of a seasonal growth pattern. Lycopodium sotae is variable with respect to leaf shape, compactness, and growth habit, probably as a response to local growth conditions, overlapping the compact aspect of the lectotype of U. aristei . In addition, several specimens identified as P. sotae (including additional isotypes ), from Argentina and Bolivia , show a similar seasonal growth pattern and adaptations to varied growth conditions. This pattern is usually less pronounced in the Bolivian specimens. Urostachys buesii Herter from Peru appears to belong in the same species, with leaf shapes similar to part of the material identified as L. sotae , including the isotype in UC, but deviates by a less seasonally affected growth pattern ( Fig. 6 ).