653 Cleal  (1935) Conserve Eusphenopteris TAXON 59 (2)  April 2010: 653–655 a consequence of van Amerom’s work, the name has become firmly embedded in the palaeobotanical literature. For instance, it has been used in the latest monographs on the Pennsylvanian (late Carbonifer- ous) aged floras of Saar-Lorraine (Laveine in Guide Paléobot. Terrain Houiller, 1989), northern Germany (Josten in Fortschr. Geol. Rheinl. Westfalen 36: 1–434. 1991; Josten & van Amerom in Fortschr. Geol. Rheinl. Westfalen 39: 1–168. 1999) and Mazon Creek (Wittry in Ma- zon Creek Fossil Fl., 2006); also in the latest species lists from Britain (Cleal in Z. Deutsch. Ges. Geowiss. 156: 387–410. 2005, in Geol. Mag. 144: 465–487. 2007), the Cantabrian Mountains (Wagner in Geol. Palaeontol. Guardo Coalfield, 1983), Nord-Pas-de-Calais (Laveine in Ann. Soc. Géol. Nord 106: 87–93. 1986), Upper Silesia and Lublin (Kotasowa & Migier in Prace Państ. Inst. Geol. 148: 56–65. 1995), Central Bohemia (Šimůnek in Geologica Balk. 34: 77–84. 2004), the Donets (Fissunenko & Laveine in Compte Rend. 9e Congr. Int. Strat. Géol. Carbon: 95–100. 1984) and northern China (Wu in Fossil Floras of China: 101. 1995). There are, however, fundamental nomenclatural difficulties sur- rounding Eusphenopteris. In a detailed analysis, Boersma & Gastaldo (in Taxon 32: 307–310. 1983) concluded that it was illegitimate, as a later homonym of Eusphenopteris Kidst., a name that had been introduced for fern fossils in which the pinnules have slender ulti- mate divisions, quite different from the lyginopteridalean fronds with usually rounded lobes that are today assigned to that name. Kidston (l.c.) gave no diagnosis for Eusphenopteris, nor did he designate a type (which was done first by Boersma & Gastaldo (l.c.), see above, although they wrongly ascribed Sphenopteris affinis to A.T. Brong- niart), but he made direct reference to the description of the intended (1935) Eusphenopteris Gothan ex Simson-Scharold in Palaeonto- graphica Abt. B, Paläophytol. 79: 37. 1934, nom. cons. prop. Typus: E. obtusiloba (Brongn.) Simson-Scharold (Sphenop- teris obtusiloba Brongn.). (H) Eusphenopteris Kidst. in Ann. Mag. Nat. Hist., ser. 5, 10: 9. 1882, nom. rej. prop. Typus (vide Boersma & Gastaldo in Taxon 32: 307. 1983): Eu- sphenopteris affinis (Lindl. & Hutton) Boersma & Gastaldo (Sphenopteris affinis Lindl. & Hutton). There is a distinctive group of fossil-species of lyginopteridalean foliage allied to Sphenopteris obtusiloba Brongn., which is unified by characters of frond architecture (van Amerom in Meded. Rijks Geol. Dienst, C-III-1 7: 1–202. 1975) and cuticular features (Bar- thel in Geologie 33: 1–140. 1962), and which most palaeobotanists nowadays recognise as a separate fossil-genus called Eusphenopteris. Twenty-five species have been assigned to the genus (Jongmans & Dijkstra in Foss. Cat. 41: 1194–1199. 1960; Jongmans & Dijkstra in Foss. Cat. 67: 3871–3872. 1967; Dijkstra & van Amerom in Foss. Cat. 89: 207–216. 1982) ranging from Namurian to Stephanian in age, and with a geographical range stretching across Euramerica and China. The most important systematic treatment of the genus was by van Amerom (l.c.) who provided a detailed emended generic diagnosis, and re-descriptions of 17 of its most commonly-found species. Based on evidence of associated ovules, van Amerom concluded that the fronds were borne by plants belonging to the Lyginopteridales. The rachis anatomy of these fronds also supports a lyginopteridalean af- finity (Shadle & Stidd in Amer. J. Bot. 62: 67–75. 1975). Largely as In the protologue of Eryngium dilatatum, Lamarck (l.c.) men- tions, besides a collection of Desfontaines, the same illustration as Linnaeus: Barrelier, l.c.: t. 36. He also mentions Boccone, which contains an illustration similar to that of Barrelier but mirror-inverted. In the text, Boccone (l.c.: 81) refers to a Spanish species, which should also grow in Italy. This is probably a result of confusion with the somewhat similar E. amethystinum L. from Italy and the Balkan Peninsula. A further reference is to Tournefort (Inst. Rei Herb. 1: 327. 1700): “Eryngium Amethystinum, Lusitanicum, minus, folio longiori”, where there is no further comment or illustration. There is no doubt that Eryngium dilatatum Lam. and E. trifidum are synonyms. According to the rules of nomenclature, the taxon growing in the Iberian Peninsula and Morocco must therefore be called E. trifidum L. In this case, however, a well-established and un- ambiguous name must be replaced. The name E. dilatatum has been in use for the Iberian species since its description in 1798. All systematic revisions and floras use this name (Delaroche, Eryng. Alep. Hist.: 26. 1808; Willkomm & Lange, Prodr. Fl. Hispan. 3: 12. 1880; Wolff in Engler, Pflanzenr. IV. 228 (Heft 61): 142. 1913; Chater in Tutin & al., Fl. Eur. 2: 323. 1968; Valdés & al., Cat. Pl. Vasc. N. Maroc 1: 472. 2002; Nieto Feliner, Fl. Iberica 10: 51. 2003; El Alaoui Faris & Ibn Tattou, Fl. Pratique Maroc 2: 291. 2007). In contrast, E. trifidum L. has never really been applied to any taxon after the publication of the first edition of Linnaeus’s Demonstrationes plantarum. This was most probably the reason for its having been considered as ambigu- ous, apart from the difficulties in consulting the rare illustration of Barrelier cited in the protologue. Rejection of Eryngium trifidum L. under ICBN Art. 56 (McNeill & al. in Regnum Veg. 146. 2006) will avoid changing a species name for purely nomenclatural reasons. As the name has not been in use for more than 250 years, its introduction would therefore cause a dis- advantageous nomenclatural change, which would be hard to accept for the users of botanic nomenclature. Acknowledgements The author thanks Charlie Jarvis, John Wiersema and John McNeill for their valuable advice and the Staats- und Universitäts- bibliothek at Göttingen for the image of the Barrelier illustration. (1935) Proposal to conserve the name Eusphenopteris Gothan ex Simson- Scharold against Eusphenopteris Kidst. (fossil Lyginopteridales ) Christopher J. Cleal Department of Biodiversity & Systematic Biology, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, U.K.; chris.cleal@museumwales.ac.uk