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 Meniscium arborescens Humb. & Bonpl. ex Willd., Sp. Pl. 5: 133. 1810 . Range:— Cuba , Dominican Republic ; southern Mexico to Bolivia (PA), Brazil , and Paraguay . Ecology:— Rare; terrestrial in humid forests; 220 m , to ca. 800 m elsewhere. Notes:— Fernandes & Salino (2020) cited a specimen from Pando , a new record for Bolivia : Manuripi, 220 m , Jimenez 1967 (NY, UC). This specimen had previously been identified by us as M. longifolium . It is a problematic specimen, not typical M. arborescens , but not M. longifolium either; pending further collections, we keep it as M. arborescens . [ Meniscium falcatum Liebm., Kongel. Danske Vidensk. Selsk. Skr., Naturvidensk. Math. Afd. , ser. 5(1): 183 (seors. 31). 1849. = Thelypteris falcata (Liebm.) R.M. Tryon, Rhodora 69(777): 6. 1967 ] Notes:— This widespread species was not included for Bolivia by Smith & Kessler (2017). However, Fernandes & Salino (2020) cited it from Cuba , southern Mexico to Panama , and Colombia and Venezuela to Bolivia , based on seven Bolivian specimens: Beck 442 (UC), Eberhardt 236 (UC), Jiménez & Gallego 1047 (UC), Kessler 9703 (UC), Kessler 11197 (UC), and “ without collector s.n .” (UC) [should be Krukoff 11128 ]. However, all of these appear to us to be typical M. pachysorum , as determined and cited by Fernandes (2015) . This species is usually readily distinguishable from M. falcatum by the long-petiolulate pinnae that are rounded at the base, these pinnae very broad (to 5 cm ) and more elliptic than lanceolate (as in M. falcatum ), and very large fronds, to 4.5 m – the key characters distinguishing M. pachysorum from M. falcatum ( Fernandes and Salino 2020 ) . In fact, Krukoff 11128 (UC) was cited in 2020 as M. falcata , “ without collector, s.n .”; specimens with this same number (from F, GH, K, MO, and NY) were cited by Fernandes & Salino (2020) as M. pachysorum . As a consequence of these possible changes of mind, resulting confusion, and our understanding of the taxonomic differences, we conclude that true M. falcatum does not occur in Bolivia , and that specimens so identified from Bolivia are all M. pachysorum .