Lectotypifications of Lìnnaean names for Flora Nordica Vol. 1 (Lycopodiaceae — Papaveraceae)

Linnaean names appearing in Volume 1 of Flora Nordica are typified. The main sources for types are the Linnaean Herbarium (LINN), the Clifford Herbarium (BM), the Burser Herbarium (UPS) the Iter lapponicum Herbarium in Paris (LAPP), and cited illustrations. The study forms part of the "Linnaean Plant Name Typification Project" based at the Natural History Museum (BM). Flora Nordica notes no. 10.     

Lectotypification of Linnaean names for Flora Nordica (Brassicaceae - Apiaceae)

Linnaean names appearing in Flora Nordica in the families Brassicaceae - Apiaceae (in the conventional family sequence of the Flora) are typified. The main sources for types are the Linnaean Herbarium (LINN), the Clifford Herbarium (BM), the Burser Herbarium (UPS) and the Iter lapponicum herbarium in Paris (LAPP), and cited illustrations. The study forms part of the "Linnaean Plant Name Typification Project" based at The Natural History Museum, London (BM). - Flora Nordica notes No. 31.     

Names,numbers and indentations: a guide to post-Linnaean taxonomy

The vast majority of biological taxonomists use the Linnaean system when constructing classifications. Taxa are assigned Linnaean ranks and taxon names are devised according to the Linnaean rules of nomenclature. Unfortunately, the Linnaean system has become theoretically outdated. Moreover, its continued use causes a number of practical problems. This paper begins by sketching the ontological and practical problems facing the Linnaean system. Those problems are sufficiently pressing that alternative systems of classification should be investigated. A number of proposals for an alternative system are introduced and evaluated. The best aspects of those proposals are brought together to form a post-Linnaean system, and a comparison of the Linnaean and post-Linnaean systems is conducted. The final section of this paper considers not only the theoretical reasons for replacing the Linnaean system, but also the practical feasibility of adopting an alternative system.     

Forum – Taxonomic Stability is Ignorance

Absolute nomenclatural stability is undesirable in phylogenetic classifications because they reflect changing hypotheses of cladistic relationships. De Queiroz and Gauthier's (1990: Syst. Zool. 39, 307–322; 1992: A. Rev. Ecol. Syst. 23, 449–480; 1994: Trends Ecol. Evol. 9, 27–31) alternative to Linnaean nomenclature is concluded to provide stable names for unstable concepts. In terms of communicating either characters shared by species of a named taxon or elements (species) included in a taxon, de Queiroz and Gauthier's system is less stable than the Linnaean system. Linnaean ranks communicate limited information about inclusivity of taxa, but abandonment of ranks results in the loss of such information. As cladistic hypotheses advance, taxa named under de Queiroz and Gauthier's system can change their level of generality radically, from being part of a group to including it, without any indicative change in its spelling. The Linnaean system has been retained by taxonomists because its hierarchic ranks are logically compatible with nested sets of species, monophyletic groups, and characters. Other authors have offered conventions to increase the cladistic information content of Linnaean names or to replace them with names that convey cladistic knowledge in greater detail; de Queiroz and Gauthier sacrifice the meaning of taxon names and categorical ranks in favor of spelling stability.     

Typification of the Linnaean names of the genus Cardamine (Cruciferae)

Lectotypification of the following Linnaean names of the genus Cardamine L. (Cruciferae) is presented Cardamine asarifolia, C. graeca, C. petraea (|M= Cardaminopsis petraea), C. resedgolia (including designation of an epitype), C. trifolia and C. virginica. The lectotypes of the previously typified names of this genus and the protologues of these names are discussed. The probable typotype for the lectotype of C. azcana is identified and the need for the conservation of the type of C. chelidonia is noted.     

The Linnaean system and its 250-year persistence

The Linnaean system of nomenclature has been used and adapted by biologists over a period of almost 250 years. Under the current system of codes, it is now applied to more than 2 million species of organisms. Inherent in the Linnaean system is the indication of hierarchical relationships. The Linnaean system has been justified primarily on the basis of stability. Stability can be assessed on at least two grounds: the absolute stability of names, irrespective of taxonomic concept; and the stability of names under changing concepts. Recent arguments have invoked conformity to phylogenetic methods as the primary basis for choice of nomenclatural systems, but even here stability of names as they relate to monophyletic groups is stated as the ultimate objective. The idea of absolute stability as the primary justification for nomenclatural methods was wrong from the start. The reasons are several. First, taxa are concepts, no matter the frequency of assertions to the contrary; as such, they are subject to change at all levels and always will be, with the consequence that to some degree the names we use to refer to them will also be subject to change. Second, even if the true nature of all taxa could be agreed upon, the goal would require that we discover them all and correctly recognize them for what they are. Much of biology is far from that goal at the species level and even further for supraspecific taxa. Nomenclature serves as a tool for biology. Absolute stability of taxonomic concepts—and nomenclature—would hinder scientific progress rather than promote it. It can been demonstrated that the scientific goals of systematists are far from achieved. Thus, the goal of absolute nomenclatural stability is illusory and misguided. The primary strength of the Linnaean system is its ability to portray hierarchical relationships; stability is secondary. No single system of nomenclature can ever possess all desirable attributes: i.e., convey information on hierarchical relationships, provide absolute stability in the names portraying those relationships, and provide simplicity and continuity in communicating the identities of the taxa and their relationships. Aside from myriad practical problems involved in its implementation, it must be concluded that “phylogenetic nomenclature” would not provide a more stable and effective system for communicating information on biological classifications than does the Linnaean system.     

Species names in phylogenetic nomenclature

Linnaean binomial nomenclature is logically incompatible with the phylogenetic nomenclature of de Queiroz and Gauthier (1992, Annu. Rev. Ecol. Syst. 23:449-480): The former is based on the concept of genus, thus making this rank mandatory, while the latter is based on phylogenetic definitions and requires the abandonment of mandatory ranks. Thus, if species are to receive names under phylogenetic nomenclature, a different method must be devised to name them. Here, 13 methods for naming species in the context of phylogenetic nomenclature are contrasted with each other and with Linnaean binomials. A fundamental dichotomy among the proposed methods distinguishes those that retain the entire binomial of a preexisting species name from those that retain only the specific epithet. Other relevant issues include the stability, uniqueness, and ease of pronunciation of species names; their capacity to convey phylogenetic information; and the distinguishability of species names that are governed by a code of phylogenetic nomenclature both from clade names and from species names governed by the current codes. No method is ideal. Each has advantages and drawbacks, and preference for one option over another will be influenced by one's evaluation of the relative importance of the pros and cons for each. Moreover, sometimes the same feature is viewed as an advantage by some and a drawback by others. Nevertheless, all of the proposed methods for naming species in the context of phylogenetic nomenclature provide names that are more stable than Linnaean binomials.     

Linnaeus's butterflies (Lepidoptera: Papilionoidea and Hesperioidea)

The names of all the species of butterflies described by Linnaeus under "Papilio" are researched. Of the 305 names treated, 243 (c. 80%) are currently valid as specific (241) or subspecific (2), 29 are junior synonyms, 14 are invalid (one of these applying to a fake), and for 13 the identity is unknown or uncertain. Six species of moths misidentified by Linnaeus as butterflies are cited in the study, but details are not included. One hundred and fifty-two lectotypes have been designated, representing about 56% of the sum of the valid names and junior synonyms. Of these, 99 were selected from specimens in the Linnean Society of London, 52 from Queen Ludovica Ulrica's collection, Uppsala, and one lectotype is a Petiver specimen from the collection of Sir Hans Sloane. Linnaeus described at least five species, possibly eight, from the literature alone. All Linnaean material examined is documented, as are 'subsequent' specimens that are associated with Linnaean material. Synonymy and homonymy are discussed and presented, as are the identities of type localities. Care has been taken to achieve a practical balance between Linnaean and current species identities. Linnaean material studied included specimens from The Linnean Society of London, Museum Ludovicae Ulricae (Uppsala University), the Clerck and De Geer collections in the Naturhistoriska Riksmuseet, Stockholm, and the collection of James Petiver, now part of the collection of Sir Hans Sloane housed in The Natural History Museum, London.     

Ceci n'est pas une pipe: names, clades and phylogenetic nomenclature

An introduction is provided to the literature and to issues relating to phylogenetic nomenclature and the PhyloCode, together with a critique of the current Linnaean system of nomenclature. The Linnaean nomenclature fixes taxon names with types, and associates the names with ranks (genus, family, etc.). In phylogenetic nomenclature, names are instead defined with reference to cladistic relationships, and the names are not associated with ranks. We argue that taxon names under the Linnaean system are unclear in meaning and provide unstable group–name associations, notwithstanding whether or not there are agreements on relationships. Furthermore, the Linnaean rank assignments lack justification and invite unwarranted comparisons across taxa. On the contrary, the intention of taxon names in phylogenetic nomenclature is clear and stable, and the application of the names will be unambiguous under any given cladistic hypothesis. The extension of the names reflects current knowledge of relationships, and will shift as new hypotheses are forwarded. The extension of phylogenetic names is, therefore, clear but is associated to (and thus dependent upon) cladistic hypotheses. Stability in content can be maximized with carefully formulated name definitions. A phylogenetic nomenclature will shift the focus from discussions of taxon names towards the understanding of relationships. Also, we contend that species should not be recognized as taxonomic units. The term ‘species’ is ambiguous, it mixes several distinct classes of entities, and there is a large gap between most of the actual concepts and the evidence available to identify the entities. Instead, we argue that only clades should be recognized. Among these, it is useful to tag the smallest named clades, which all represent non-overlapping groups. Such taxa  – LITUs (Least Inclusive Taxonomic Units) – are distinguished from more inclusive clades by being spelled with lower-case initial letter. In contrast to species, LITUs are conceptually straightforward and are, like other clades, identified by apomorphies.     

Lectotypification of the Linnaean names Thalictrum angustifolium and T. lucidum (Ranunculaceae)

Two further Linnaean names of Thalictrum are lectotypified. Thalictrum lucidum has priority over angustifolium. — Flora Nordica Notes no. 30.     

Stems,nodes, crown clades,and rank‐free lists: is Linnaeus dead?

Recent radical proposals to overhaul the methods of biological classification are reviewed. The proposals of phylogenetic nomenclature are to translate cladistic phylogenies directly into classifications, and to define taxon names in terms of clades. The method has a number of radical consequences for biologists: taxon names must depend rigidly on the particular cladogram favoured at the moment, familiar names may be reassigned to unfamiliar groupings, Linnaean category terms (e.g. phylum, order, family) are abandoned, and the Linnaean binomen (e.g. Homo sapiens) is abandoned. The tenets of phylogenetic nomenclature have gained strong support among some vocal theoreticians, and rigid principles for legislative control of clade names and definitions have been outlined in the PhyloCode. The consequences of this semantic maelstrom have not been worked out. In pratice, phylogenetic nomenclature will bc disastrous, promoting confusion and instability, and it should be abandoned. It is based on a fundamental misunderstanding of the difference between a phylogeny (which is real) and a classification (which is utilitarian). Under the new view, classifications are identical to phlylogenies, and so the proponents of phylogenetic nomenclature will end up abandoning classifications altogether.     

Typification of the Linnaean names in Pyrola (Ericaceae,Pyroloideae)

Lectotypes are designated for four of the six Linnaean names inPyrola. The names are applied now to species ofChimaphila, Moneses, Orthilia, andPyrola (Ericaceae, Pyroloideae).     

Type specimens of Mitridae (Mollusca:Gastropoda) described by Linnaeus in the genera Voluta, Buccinum and Bulla between 1758 and 1771

From the 16 species of Mitridae described by Linnaeus between the years 1758-71 11 species are considered valid and available for taxonomic use; four specific names have been suppressed by the International Commission on Zoological Nomenclature for taxonomic usage (1968). One specific name, i.e. Voluta mitra episcopalis Linnaeus, has appeared in various combinations in malacological literature over the years. From the style of listing in the 10th edition of the Systerna Naturae , it is evident that 'episcopalis' has to be treated as of infraspecific rank; there is no evidence that 'episcopalis' is even a valid subspecies of Voluta mitra.
Three holotypes and five lectotypes designated in this paper are extant in the Linnaean collection; illustrations representing three Linnaean species have been selected as lectotypes.     

A higher-level taxonomy for hummingbirds

In the context of a recently published phylogenetic estimate for 151 hummingbird species, we provide an expanded informal taxonomy, as well as a formal phylogenetic taxonomy for Trochilidae that follows the precepts of the PhyloCode, but remains consistent with the hierarchical nomenclature of the Linnaean system. We compare the recently published phylogenetic hypothesis with those of prior higher-level and more taxonomically circumscribed phylogenetic studies. We recommend the recognition of nine new clade names under the PhyloCode, eight of which are consistent with tribes and one with a subfamily under the Linnaean system.     

Least-inclusive taxonomic unit: a new taxonomic concept for biology

Phylogenetic taxonomy has been introduced as a replacement for the Linnaean system. It differs from traditional nomenclature in defining taxon names with reference to phylogenetic trees and in not employing ranks for supraspecific taxa. However, 'species' are currently kept distinct. Within a system of phylogenetic taxonomy we believe that taxon names should refer to monophyletic groups only and that species should not be recognized as taxa. To distinguish the smallest identified taxa, we here introduce the least-inclusive taxonomic unit (LITU), which are differentiated from more inclusive taxa by initial lower-case letters. LITUs imply nothing absolute about inclusiveness, only that subdivisions are not presently recognized.     

The first valid publication of the Linnaean Mnium triquetrum (Musci) and other new names for mosses proposed by N. Jolyclerc

A brief biographical sketch of Nicolas-Marie-Thérèse Jolyclerc (1746–1817), the French naturalist and adherent of C. Linnaeus, is presented. The publication history of his Système sexuel des végétaux, the first French version of the Linnaean sexual system of the plants is outlined. Apart from the well-known editions of this work of 1797, 1798 and 1810, a neglected edition of 1803 is described, and it is shown that this is not a pirated edition as has been suggested. A list of fourteen new combinations in mosses proposed by N. Jolyclerc in the 1803 edition of Système sexuel des végétaux is presented and some names are briefly annotated. Additionally, it is shown that Mnium triquetrum, basionym of the well-known moss species Meesia triquetra, was validly published for the first time by N. Jolyclerc in 1803, not by H. E. Richter in 1839 as is commonly accepted. Accordingly, the correct author citation for Meesia triquetra should be ‘(L. ex Jolycl.) Ångstr.’, not ‘(L. ex Richt.) Ångstr.’ The lectotype of Mnium triquetrum L. ex Jolycl. is selected from the Linnaean herbarium (LINN).     

Rank and sequence in Caspar Bauhin's Pinax

CAIN, A. J., 1994. Rank and sequence in Caspar Bauhin's Pinax. Bauhin's consistent use of genera, species and binominals, applauded by historians as anticipating Linnaeus's theory and practice, does not appear on closer examination to be intended as anything of the sort. His use of the terms genus and species is as in Aristotelian logic, with a shifting reference, at all taxonomic levels. His typographical layout, emphasizing (but far from invariably employing) single-word names for effectively generic entities, often qualified by ‘and its species’, gives the impression of Linnaean practice, and coincides with it not infrequently, but not with Linnaean theory. The main entities for which it can be said that Bauhin uses fairly consistently a biverbal binominal name-phrase, like Linnaeus' trivial names, were in fact in Linnaeus's eyes two levels of supraspecific groupings. The main entities in Bauhin which Linnaeus recognized as species, as is shown by his quotations in the Species plantarum, are subdivisions of his biverbally or nearly biverbally named groupings, but themselves have multiverbal names. These correspond closely to Linnaeus's diagnostic specific names, not at all to his biverbal trivial names. Bauhin probably had no conception of the species and genus as ranks in the modern sense, first adumbrated by Tournefort and utilized by Linnaeus. Bauhin certainly tried to group forms by natural affinity, as did Theophrastus before him and Linnaeus afterwards. Not being alerted to the importance of the details of the flower and fruit, he used what characters he could find, notably, but not by any means exclusively, leaf shape. He composed the Pinax as a nomenclatural concordance to earlier authors, notably Dioscorides, Theophrastus and Pliny. He retained the sequence of major groups of Theophrastus (as the greatest authority on plants) but reversed it to start with the best-known plants, grasses. Where Theophrastus gave no help, in the cryptogams, Bauhin inserted as a pendant his own series from ferns down to fungi, using the Aristotelian principles of the gradation of forms. His overall arrangement, therefore, is not a simple progression but a chain with pendants. Bauhin is far closer to earlier authors than to Linnaeus, but his typography, along with other authors, may well have helped to incite Linnaeus to a more rigorous and consistent use of ranked groups and biverbal names.     

Should taxon names be explicitly defined?

Overviews are provided for traditional and phylogenetic nomenclature. In traditional nomenclature, a name is provided with a type and a rank. In the rankless phylogenetic nomenclature, a taxon name is provided with an explicit phylogenetic definition, which attaches the name to a clade. Linnaeus’s approach to nomenclature is also reviewed, and it is shown that, although the current system of nomenclature does use some Linnaean conventions (e.g., certain rank-denoting terms, binary nomenclature), it is actually quite different from Linnaean nomenclature. The primary differences between traditional and phylogenetic nomenclature are reviewed. In phylogenetic nomenclature, names are provided with explicit phylogenetic definitions, whereas in traditional nomenclature names are not explicitly defined. In phylogenetic nomenclature, a name remains attached to a clade regardless of how future changes in phylogeny alter the clade’s content; in traditional nomenclature a name is not “married” to any particular clade. In traditional nomenclature, names must be assigned ranks (an admittedly arbitrary process), whereas in phylogenetic nomenclature there are no formal ranks. Therefore, in phylogenetic nomenclature, the name itself conveys no hierarchical information, and the name conveys nothing regarding set exclusivity. It is concluded that the current system is better able to handle new and unexpected changes in ideas about taxonomic relationships. This greater flexibility, coupled with the greater information content that the names themselves (i.e., when used outside the context of a given taxonomy or phytogeny) provide, makes the current system better designed for use by all users of taxon names.