Page  63 ï~~2007 THE MICHIGAN BOTANIST 63 AUTHORSHIP OF THE NAME CENTAURIUM PULCHELLUM (GENTIANACEAE) James S. Pringle Royal Botanical Gardens P.O. Box 399, Hamilton, Ontario, Canada L8N 3H8 jpringle@rbg.ca ABSTRACT Valid publication of the combination Centaurium pulchellum should be attributed to (Swartz) Hayek ex Handel-Mazzetti et al. KEY WORDS: Centaurium, Gentianaceae, nomenclature Centaurium pulchellum, the lesser or branching centaury, is native to Eurasia and widely naturalized elsewhere. In North America, where it has been known as a naturalized species for about two centuries, most of its populations are in the East and the Great Lakes region, with isolated occurrences south to the Gulf Coastal region and west to California and Washington. In Michigan, especially, it has increased conspicuously in recent years. Authorship of the binomial Centaurium pulchellum is usually attributed to "(Sw.) Druce, Fl. Berks. 342. 1897." As noted in The International Plant Names Index (http://www.ipni.org/index.html; accessioned 5 Jun 2007), however, in The Flora of Berkshire (1898) Druce published this combination only as a provisional name that would become appropriate if the genus name Centaurium Hill should be adopted. At that time Druce accepted Erythraea, with its authorship attributed to Richard, as the correct name for the genus, and E. pulchella (Swartz) E. M. Fries as the correct name for the species, Gentiana pulchella Swartz being the basionym. In some references the combination C. pulchellum is attributed to "(Sw.) Druce, Fl. Oxf. 342. 1897," but this is simply an error for "Fl. Berks." In The Flora of Oxfordshire, ed. 1 (Druce 1886), Erythraea is the accepted name for the genus. Druce was aware of Hill's (1756-1757) The British Herbal, in which Hill had published the generic name Centaurium, and he later advocated the acceptance of generic names of pre-Linnaean origin as having been validly published in that work. As of 1898, however, this was a matter of controversy, because Hill had not adhered to the binomial format for the names of species (Barnhart 1899; Stearn 1967). Druce did use the name Centaurium pulchellum in later publications, after the generic name Centaurium had become widely accepted, but in the interim other works pertinent to this topic were published. A few recent authors, mostly European, have attributed the combination C. pulchellum to E. H. L. Krause, but Krause (1903) likewise published it only as a provisional name. His treatment of the genus is headed: Tausendgiildenkriauter, Erythraea. The generic name Centaurium is mentioned only in the text,

Page  64 ï~~64 THE MICHIGAN BOTANIST Vol. 46 as a synonym. His wording for the species is: Kleines Tausendgtildenkriuter, Erythraea pulchella oder Centaurium pulchellum [fonts as in original]. No authorship was cited for the provisional name. One other attribution of the authorship is listed in The International Plant Names Index, to "Hayek, Oesterr. Bot. Z. 56: 70. 1906," but that is not entirely correct either. In that publication, Handel-Mazzetti et al. (1906) accepted the binomial Centaurium pulchellum (as Centaurion, an orthographic variant) which they attributed to "(Sw.) Hayek in litt." They did not cite any publication by Hayek in this context, nor did they indicate that Hayek participated in the authorship of the work in which the combination was published. A search for early works in which the generic name Centaurium (or Centaurion) had been accepted disclosed none earlier in which the name C. pulchellum was accepted. Therefore, in accord with Articles 46.4 and 46.7, Ex. 36, and Recommendation 46C.2 of the International Code of Botanical Nomenclature (McNeill et al. 2006), authorship and valid publication of the combination Centaurium pulchellum should be attributed to (Swartz) Hayek ex Handel-Mazzetti et al., Oesterr. Bot. Z. 56: 70. 1906. ACKNOWLEDGMENTS I am grateful to the library staff of the University of Michigan and the Missouri Botanical Garden for access to historic publications. This paper is Contribution No. 175 from the Royal Botanical Gardens, Hamilton, Ontario, Canada. LITERATURE CITED Barnhart, J.H. (1899). Nomenclatural notes.-II. Bull. Torrey Bot. Club 26: 376-380. Druce, G.C. (1886). The Flora of Oxfordshire, being a Topographical and Historical Account of the Flowering Plants and Ferns Found in the County with Sketches of the Progress of Oxfordshire Botany During the Last Three Centuries, ed. 1. Parker & Co., Oxford and London. Druce, G.C. ("1897" [1898]). The Flora of Berkshire, being a Topographical and Historical Account of the Flowering Plants and Ferns Found in the County with Short Biographical Notices of the Botanists who have Contributed to Berkshire Botany During the Last Three Centuries. Clarendon Press, Oxford. Handel-Mazzetti, H.F. von, J. Stadlmann, E. Janchen, and F. Faltis. (1906). Beitrag zur Kenntnis der Flora von West-Bosnien. Oesterr. Bot. Z. 56: 69-79. Hill, J. ("1756" [1756-1757]). The British Herbal: An History of Plants and Trees, Native of Britain, Cultivated for Use, or Raised for Beauty. T. Osborne and J. Shipton, London, U.K. Krause, E.H.L. (1903). J. Sturm's Flora von Deutschland in Abbildungen nach des Natur [ed. 2]. R6hrenbltitler [sic] in weiteren Sinne. Tubatae. 10. Band: 1. Hilfte. Schriften Deutsch. LehrerVereins Naturk. 12. McNeill, J., F.R. Barrie, H.M. Burdet, V. Demoulin, D.L. Hawksworth, K. Marhold, D.H. Nicholson, J. Prado, P.C. Silva, J.E. Skog, J.H. Wiersema, and N.J. Turland, eds. (2006). International Code of Botanical Nomenclature (Vienna Code). Regnum Veg. 146. Stearn, W.T. (1967). Hill's The British Herbal (1756-1757). Taxon 16: 494-498.