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 Campyloneurum Smith et al . (2018) treated 26 species for the genus Campyloneurum for Bolivia . Since then, Labiak et al . (2020) have described an additional species, C. atrosquamatum , with type from Amazonian Ecuador , which also occurs in Bolivia . Specimens of the new species have previously mostly been identified as C. coarctatum but are phylogenetically closer to C. fuscosquamatum . In the key to the Bolivian species of Campyloneurum of Smith et al . (2018), this species would key to lead 25, where it would not key out further because it combines traits of both leads. We thus here provide an updated version of the key starting with lead 25: 25 Rhizome scales linear-lanceolate,>10 times longer than broad, non-clathrate, the cell lumina occluded or narrow and yellowish. ......................................................................................................................................................................................................... 26 - Rhizome scales lanceolate to ovate, <8 times longer than broad, non-clathrate or clathrate, the cell lumina hyaline or yellowish. ......................................................................................................................................................................................................... 27 26 Petioles 5–19 cm long; lamina bases concave ..................................................................................................... C. atrosquamatum - Petioles 1–5 cm long; lamina bases tapered ...................................................................................................... C. fuscosquamatum 27 Laminar bases cuneate, short-decurrent; petioles usually at least 1/3 the length of the laminae ................................................... 28 - Laminar bases gradually decurrent; petioles usually less than 1/3 the length of the laminae ........................................................ 29 28 Rhizome scales lanceolate, peltate or biauriculate at their bases, slightly clathrate, except some cells along middle of scales; cell lumina slightly yellowish ............................................................................................................................................. C. sphenodes - Rhizome scales basifixed or shortly biauriculate at their bases, strongly clathrate; cell lumina hyaline ................... C. coarctatum 29 Rhizome scales ovate, adpressed, apices obtuse, scale margins slightly differentiated, with 3 or more rows of thin-walled cells .... ................................................................................................................................................................................... C. ophiocaulon - Rhizome scales narrowly-ovate, spreading, apices acuminate, scale margins undifferentiated or with 2 rows of thin-walled cells. ......................................................................................................................................................................................................... 30 30 Rhizome scales bicolorous, margins with 2 rows of thin-walled cells ............................................................................... C. repens - Rhizome scales concolorous, margins not clearly differentiated ............................................................................. C. serpentinum