STATUS, TYPIFICATION, AND PRIORITY OF NAMES
LIMITATION OF THE PRINCIPLE OF PRIORITY
13.1. Valid publication of names for organisms of different groups is treated as beginning at the following dates (for each group a work is mentioned that is treated as having been published on the date given for that group):
(a) Spermatophyta and Pteridophyta, names at ranks of genus and below, 1 May 1753 (Linnaeus, Species plantarum, ed. 1); suprageneric names, 4 August 1789 (Jussieu, Genera plantarum).
(b) Musci (except Sphagnaceae), 1 January 1801 (Hedwig, Species muscorum frondosorum).
(c) Sphagnaceae and Hepaticae (including Anthocerotae), names at ranks of genus and below, 1 May 1753 (Linnaeus, Species plantarum, ed. 1); suprageneric names, 4 August 1789 (Jussieu, Genera plantarum).
(e) Algae, 1 May 1753 (Linnaeus, Species plantarum, ed. 1). Exceptions:
Nostocaceae homocysteae, 1 January 1892 (Gomont, “Monographie des Oscillariées”, in Ann. Sci. Nat., Bot., ser. 7, 15: 263–368; 16: 91–264). The two parts of Gomont’s “Monographie”, which appeared in 1892 and 1893, respectively, are treated as having been published simultaneously on 1 January 1892.
Nostocaceae heterocysteae, 1 January 1886 (Bornet & Flahault, “Révision des Nostocacées hétérocystées”, in Ann. Sci. Nat., Bot., ser. 7, 3: 323–381; 4: 343–373; 5: 51–129; 7: 177–262). The four parts of the “Révision”, which appeared in 1886, 1886, 1887, and 1888, respectively, are treated as having been published simultaneously on 1 January 1886.
Desmidiaceae (s. l.), 1 January 1848 (Ralfs, British Desmidieae).
Oedogoniaceae, 1 January 1900 (Hirn, “Monographie und Iconographie der Oedogoniaceen”, in Acta Soc. Sci. Fenn. 27(1)).
Fossil organisms (diatoms excepted):
(f) All groups, 31 December 1820 (Sternberg, Flora der Vorwelt, Versuch 1: 1–24, t. 1–13). Schlotheim’s Petrefactenkunde (1820) is regarded as published before 31 December 1820.
Ex. 1. The genus Porella and its single species, P. pinnata, were referred by Linnaeus (Sp. Pl.: 1106. 1753) to the Musci; because the type specimen of P. pinnata is now accepted as belonging to the Hepaticae, the names were validly published in 1753.
Ex. 2. The designated type of Lycopodium L. (Sp. Pl.: 1100. 1753) is L. clavatum L. (l.c.: 1101. 1753), the type specimen of which is currently accepted as a pteridophyte. Accordingly, although the genus is listed by Linnaeus among the Musci, the generic name and the names of the pteridophyte species included by Linnaeus under it were validly published in 1753.
13.3. For nomenclatural purposes, a name is treated as pertaining to a non-fossil taxon unless its type is fossil in origin (Art. 1.2). Fossil material is distinguished from non-fossil material by stratigraphic relations at the site of original occurrence. In cases of doubtful stratigraphic relations, and for all diatoms, provisions for non-fossil taxa apply.
13.4. Generic names that appear in Linnaeus’s Species plantarum, ed. 1 (1753) and ed. 2 (1762–1763), are associated with the first subsequent description given under those names in Linnaeus’s Genera plantarum, ed. 5 (1754) and ed. 6 (1764). The spelling of the generic names included in Species plantarum, ed. 1, is not to be altered because a different spelling has been used in Genera plantarum, ed. 5.
Note 1. The two volumes of Linnaeus’s Species plantarum, ed. 1 (1753), which appeared in May and August, 1753, respectively, are treated as having been published simultaneously on 1 May 1753 (Art. 13.1).
Ex. 3. The generic names Thea L. (Sp. Pl.: 515. 24 May 1753; Gen. Pl., ed. 5: 232. 1754) and Camellia L. (Sp. Pl.: 698. 16 Aug 1753; Gen. Pl., ed. 5: 311. 1754) are treated as having been published simultaneously on 1 May 1753. Under Art. 11.5, the combined genus bears the name Camellia because Sweet (Hort. Suburb. Lond.: 157. 1818), who was the first to unite the two genera, chose that name and cited Thea as a synonym.
Ex. 4. Sideroxylon L. (Sp. Pl.: 192. 1753) is not to be altered because Linnaeus spelled it ‘Sideroxylum’ in Genera plantarum, ed. 5 (p. 89. 1754); usage of Brunfelsia L. (Sp. Pl.: 191. 1753, orth. cons., ‘Brunsfelsia’), which Linnaeus adopted in 1754, has been made possible only through conservation (see App. III).