(2942) Proposal to conserve the name <i>Dicksonia bipinnata</i> (<i>Dennstaedtia bipinnata</i>, <i>Mucura bipinnata</i>) (<i>Dennstaedtiaceae</i>) with a conserved type

(2942) Dicksonia bipinnata Cav., Descr. Pl.: 274. 1802 (ante 2 Mar), nom. cons. prop. Typus: [Puerto Rico?], Ventenat (B-W barcode B -W 20165 -01 0; isotypus: US No. 1148434 [barcode 00745250] [fragm.]), typ. The Dennstaedtiaceae is a medium-sized family of ferns with puzzling nomenclatural history and issues, either by the numerous species conceptions rank adoptions within bracken – for example, epithet Pteridium arachnoideum (Kaulf.) Maxon has also been used at three infraspecific ranks under different or conservation proposals to maintain stability in family. There are least two conserved names (Pteris arachnoidea Kaulf. Hypolepis nigrescens Hook. see App. IV ICN; Turland & al., Regnum Veg. 159. 2018), and, among its 11 currently recognized genera, proposed conservation: Dennstaedtia, prop.; Microlepia, Pteridium, (see https://naturalhistory2.si.edu/botany/codes-proposals/). Within last decade, phylogenetic works have demonstrated paraphyly such as Perrie al. (in Austral. Syst. Bot. 28: 256–264. 2015), Schneider Perspect. Pl. Ecol. Evol. 18: 70–78. 2016), Shang Molec. Phylogen. 127: 449–458. Schwartsburd 150: 106881. 2020). (l.c.) were first organize subfamily Hypolepidoideae into monophyletic describing new genus Hiya H. slightly altering previous circumscription Bernh. Just recently, Triana-Moreno Taxon 71: 688–690. 2022, 72: 20–46. 2023) dealt Dennstaedtioideae, making substantial changes generic circumscriptions (especially Dennstaedtia s.str.), resurrecting Sitobolium Desv. from synonymy, Mucura L.A. Triana Sundue accommodate Neotropical previously known “alate Dennstaedtia”: M. (Cav.) globulifera (Poir.) Sundue, former taken type. But just when systematics appeared be finally resolved, issue came along: there serious historical problem type Cav. (and thus, newly described Mucura), that needs exposed solved. We explain it below propose reasonable solution. was Cavanilles (Descr. 1802), based on specimen sent Ventenat, without location data. According Stafleu Cowan 94 [TL-2, 1]: 471. 1976), already established Madrid botanical garden (MA), so his types expected there. During our search, we found matches Cavanilles's description name “Dicksonia bipinnata” label: MA 213495 (available at: http://161.111.171.57/herbarioV/visorVCat.php?img=MA-01-00213495). This consists part leaf, representing bipinnate-pinnatifid plant. no adaxial wings connect an axis onto next order axes, which one main characters defining (= Dennstaedtia”), helps easily diagnose it. In other words, does not represent provided intended (l.c. 2023: 40); s.str. should, fact, treated synonym dissecta (Sw.) T. Moore, if strictly follow rules Code (Art. 7 11). By extension, becomes s.str., alate s.l. will need placed as-yet-unnamed genus, them requiring specific epithet. But, entirely responsible this confusion. puzzle started 1810, Willdenow adiantoides Humb. Bonpl. ex Willd. (Sp. 5: 488. 1810). did explicitly cite specimens, but he cited locations (Caripe, Hispaniola, Puerto Rico), Plumier plate (Traité Foug. Amér.: t. 30. 1705), synonymy. Christensen Dansk Ark. 9: 26. 1937) Proc. Biol. Soc. Wash. 51: 39–40. 1938) determined Caripe referred Humboldt Bonpland B-W (barcode -02 0, available https://herbarium.bgbm.org/object/BW20165020), Hispaniola Plumier's (l.c.), Rico synonymy D. bipinnata) (B https://herbarium.bgbm.org/object/BW20165010), fragment later forwarded 00745250). tripinnate-pinnatifid has, indeed, typical adaxial, connecting present Dennstaedtia” (or Mucura, proposes). conclusion, specimens do correspond same taxonomic entity; they species; even genera sensu 2023). interpretation, should considered duplicates. As suggested, would come plant cultivated European gardens, whereas believed really Rico. It very probable (at B-W) duplicate specimen, since synoymyzed led speculate Willdenow's change epithet, adiantoides, due morphological inaccuracy. misinterpretation identity these MA) persisted (l.c.). suspected duplicates suggested synonymyzed bipinnata, latter had priority. accepted Christensen's ideas formally synonymized combined Maxon, although admitted herbarium “almost certainly original collection” [of bipinnata]. Having seen only US, failed indicate MA). Tryon, who made revision modern format Contr. Gray Herb. 187: 23–52. 1960), added further Tryon (l.c.: 40–41) citing holotype (although seeing it), isotype (neither (the actually saw). bipinnata. Furthermore, circumscribed having laminae wings. appears consolidated “isotype” B-W, followed every pteridologist nearly flora. For Proctor Jamaica (Ferns Jamaica: 168–169. 1985) Virgin Islands Mem. New York Gard. 53: 100–101. 1989), Stolze Peru Fieldiana, 22: 99. Cranfill U.S.A. (Florida) FNA Ed. Comm., Fl. N. Amer. Mexico 2: 200. 1993), Moran Mesoamerica Davidse Mesoamer. 1: 152. 1995), Smith Venezuelan Guiana Berry Venez. 50. Navarrete Øllgaard Ecuador Nordic J. 20: 327–329. 2000), Mickel (Pterid. Mexico: 245. 2004), Murillo-Pullido Colombia Colombia: 85. 2008), Bolivia Phytotaxa 332: 253. 2017), Brazil Flora Brasil 2020, http://floradobrasil.jbrj.gov.br/reflora/floradobrasil/FB90915), on. Most authors (with US), none ever material MA. neither nor MA, admitted. confusion culminates Mucura. their “Mucura L.A.Triana (≡ Cav.)”. Although specify any must Cavanilles. Despite long being (from Willdenow, l.c. Triana-Moreno, 2023), absolutely evidence apparent contact specimen; disagrees protologue (it tripinnate-pinnatifid!); probably gathering than specimen. Therefore, typification “holotype: isotype: B-W” (or, lectotype isolectotype current understanding Art. 9.10) flawed. far know, specimen: On hand, conception built false largely adopted over 85+ years, culminating recent (Mucura), understand strict application ICN disadvantageous. Thus, commonly (now 14), prevent loss type: duplicate/fragment US). If approved, longer NTLP, https://orcid.org/0000-0002-3145-8183 PBS, https://orcid.org/0000-0002-5305-9300 thank John McNeill Wiersema suggestions, editing, handling manuscript. NTLP thanks FAPEMIG (for Doctoral grant) IAPT (research grant PBS research APQ-00935-22).