A name published on or after 1 January 1953 without a clear indication of the rank of the taxon concerned is not validly published.
For suprageneric names published on or after 1 January 1887, the use of one of the terminations specified in Art. 16.3, 17.1, 18.1, 19.1, and 19.3 is accepted as an indication of the corresponding rank, unless this (a) would conflict with the explicitly designated rank of the taxon (which takes precedence), (b) would result in a rank sequence contrary to Art. 5 (in which case Art. 37.6 applies), or (c) would result in a rank sequence in which the same rank-denoting term occurs at more than one hierarchical position.
Jussieu (in Mém. Mus. Hist. Nat. 12: 497. 1827) proposed Zanthoxyleae without specifying the rank. Although he employed the present termination for tribe (-eae), that name, being published prior to 1887, is unranked. Zanthoxyleae Dumort. (Anal. Fam. Pl.: 45. 1829), however, is the name of a tribe, as Dumortier specified its rank.
Nakai (Chosakuronbun Mokuroku [Ord. Fam. Trib. Nov.]. 1943) validly published the names Parnassiales,Lophiolaceae,Ranzanioideae, and Urospatheae. He indicated the respective ranks of order, family, subfamily, and tribe, by virtue of their terminations even though he did not mention these ranks explicitly.
A name published before 1 January 1953 without a clear indication of its rank is validly published provided that all other requirements for valid publication are fulfilled; it is, however, inoperative in questions of priority except for homonymy (see Art. 53.4). If it is the name of a new taxon, it may serve as a basionym or replaced synonym for subsequent new combinations, names at new ranks, or replacement names in definite ranks.
The unranked groups “Soldanellae”,“Sepincoli”,“Occidentales”, etc., were published under Convolvulus L. by House (in Muhlenbergia 4: 50. 1908). The names C. [unranked] Soldanellae House, etc., are validly published names but have no status in questions of priority except for purposes of homonymy under Art. 53.4.
In Carex L., the epithet Scirpinae was used in the name of an unranked subdivision of a genus by Tuckerman (Enum. Meth. Caric.: 8. 1843); this taxon was assigned sectional rank by Kükenthal (in Engler, Pflanzenr. IV. 20 (Heft 38): 81. 1909) and its name is then cited as Carex sect. Scirpinae (Tuck.) Kük. (C. [unranked] Scirpinae Tuck.).
Loesener published “Geranium andicola var. vel forma longipedicellatum” (Bull. Herb. Boissier, ser. 2, 3(2): 93. 1903) with an ambiguous indication of infraspecific rank. The name is correctly cited as “G. andicola [unranked] longipedicellatum Loes.” The epithet was used in a subsequent combination, G. longipedicellatum (Loes.) R. Knuth (1912).
If in one whole publication (Art. 37.5), prior to 1 January 1890, only one infraspecific rank is admitted, it is considered to be that of variety unless this would be contrary to the author’s statements in the same publication.
In questions of indication of rank, all publications appearing under the same title and by the same author, such as different parts of a flora issued at different times (but not different editions of the same work), must be considered as a whole, and any statement made therein designating the rank of taxa included in the work must be considered as if it had been published together with the first instalment.
In Link’s Handbuch (1829–1833) the rank-denoting term “O.” (ordo) was used in all three volumes. These names of orders cannot be considered as having been published as names of families (Art. 18.2) since the term family was used for Agaricaceae and Tremellaceae under the order Fungi in vol. 3 (pp. 272, 337; see Art. 18 Note 3). This applies to all three volumes of the Handbuch even though vol. 3 was published later (Jul–29 Sep 1833) than vols. 1 and 2 (4–11 Jul 1829).
A name is not validly published if it is given to a taxon of which the rank is at the same time, contrary to Art. 5, denoted by a misplaced term. Such misplacements include forms divided into varieties, species containing genera, and genera containing families or tribes.
Only those names published with the rank-denoting terms that must be removed so as to achieve a proper sequence are to be regarded as not validly published. In cases where terms are switched, e.g. family-order, and a proper sequence can be achieved by removing either or both of the rank-denoting terms, names at neither rank are validly published unless one is a secondary rank (Art. 4.1) and one is a principal rank (Art. 3.1), e.g. family-genus-tribe, in which case only names published at the secondary rank are not validly published.
“Sectio Orontiaceae” (Brown, Prodr.: 337. 1810) is not a validly published name, since Brown misapplied the term “sectio” to a rank higher than genus.
“Tribus Involuta” and “tribus Brevipedunculata” (Huth in Bot. Jahrb. Syst. 20: 365, 368. 1895) are not validly published names, since Huth misapplied the term “tribus” to a rank lower than section, within the genus Delphinium.
Sequential use of the same rank-denoting term in a taxonomic sequence does not represent misplaced rank-denoting terms.
Danser (in Recueil Trav. Bot. Néerl. 18: 125–210. 1921) published ten names of new subspecies in a treatment of Polygonum in which he recognized subspecies (indicated by Roman numerals) within subspecies (indicated by Arabic numerals). These do not represent misplaced rank-denoting terms, Art. 37.6 does not apply, and the names are validly published.
Situations where the same rank-denoting term is used at more than one non-successive position in the taxonomic sequence represent informal usage of rank-denoting terms. Names published with such rank-denoting terms are treated as unranked (see Art. 37.1 and 37.3).
Names published with the term “series” by Bentham & Hooker (Gen. Pl. 1–3. 1862–1883) are treated as unranked because this term was used at seven different hierarchical positions in the taxonomic sequence. Therefore, the sequence in Rhynchospora (3: 1058–1060. 1883) of genus-“series”-section does not contain a misplaced rank-denoting term.
An exception to Art. 37.6 is made for names of the subdivisions of genera termed tribes (tribus) in Fries’s Systema mycologicum, which are treated as validly published names of unranked subdivisions of genera.
Agaricus “tribus” Pholiota Fr. (Syst. Mycol. 1: 240. 1821), sanctioned in the same work, is the validly published basionym of the generic name Pholiota (Fr. : Fr.) P. Kumm. (1871) (see Art. 41 Ex. 6).
