# Bulletin of the Torrey Botanical Club/Volume 34/American Code of Botanical Nomenclature

* AMERICAN CODE OF BOTANICAL NOMENCLATURE
The Nomenclature Commission has carefully examined the rules and recommendations adopted by the International Botanical Congress held at Vienna in June, 1905, and compared them with the canons unanimously approved by them at their meeting held in Philadelphia in March, 1904, which were duly transmitted to the Vienna Congress.
The Vienna Congress decided to base its deliberations and its code on the code of nomenclature adopted by the Botanical Congress held in Paris in 1867.   At the Philadelphia meeting above referred to, this Commission concluded that better results would be obtained by abandoning the Paris code altogether and substituting for it a simpler set of rules,* more satisfactorily arranged, which should recognize and emphasize the method of establishing and maintaining botanical names by the method of types.  The Vienna Congress failed to recognize the principle of types, however, although its results are an advance in several ways over the Paris rules of 1867.  This Commission is still of the opinion that the method by types will obtain general recognition and acceptance, inasmuch as it is the only one which promises sufficient definiteness to answer present requirements in biological nomenclature.  The present discussion of this subject by zoologists is illuminating and will lead to important results.  To reach greater precision we suggest certain modifications of the rules governing the selection of types enunciated at our Philadelphia meeting.
* Bull. Torrey Club 31 : 249-261.   1904.
The Vienna Congress voted unanimously that the principles of nomenclature should not be arbitrary, but subsequently adopted, though not unanimously, a list of several hundred generic names of plants to be excluded from the operation of all nomenclatorial rules.   We regard this action as in the highest degree arbitrary, as controverting a cardinal principle; and no method is provided for fixing the types of the genera which it is proposed to maintain or reject.
The treatment of homonyms was not given the importance at Vienna that this Commission believes necessary, although we are now of the opinion that the canons of the Philadelphia code relating to homonyms were framed in a somewhat more exclusive manner than is desirable, and we recommend some amendments to these canons.
It was unanimously agreed at Vienna to maintain the oldest specific name when a species is transferred from one genus to another, or the oldest subspecific or varietal name when a subspecies or variety is transferred from one species to another; but, when the rank is changed from species to subspecies or variety, or vice versa, the name need not be maintained, although it is desirable that it should be.   To meet this agreement the Philadelphia code requires modifications, as shown by the amendments herewith recommended.
By a close vote, the Vienna Congress called for all descriptions of new species or genera, published after January 1, 1908, to be accompanied by a diagnosis in the Latin language.   This requirement reaches the height of arbitrary action, and we do not regard the subject as one over which any botanical congress has jurisdiction.  The progressive disuse of Latin, its elimination from the curricula of scientific schools, and the general teaching of two or more modern languages, lead us to regard this action as unnecessary and unwise.
We recommend that the Code adopted at Philadelphia be maintained, as amended, as follows.
| J. C. Arthur. | Arthur Hollick. |
| John Hendley Barnhart. | Marshall A. Howe. |
| N. L. Britton. | F. H. Knowlton. |
| Frederic E. Clements. | George T. Moore. |
| O. F. Cook. | H. H. Rusby. |
| Frederick V. Coville. | C. L. Shear. |
| F. S. Earle. | Lucien M. Underwood. |
| Alexander W. Evans. | David White. |
| Tracy E. Hazen. | William F. Wight. |
Members and Alternates of the Nomenclature Commission of the Botanical Club of the American Association for the Advancement of Science.
* CODE
* Part I: Principles.
| 1. | The primary object of formal nomenclature in systematic biology is to secure stability, uniformity and convenience in the designation of plants and animals. |
| 2. | Botanical nomenclature is treated as beginning with the general application of binomial names of plants (Linnaeus' Species Plantarum, 1753). |
| 3. | Priority of publication is a fundamental principle of botanical nomenclature.   Two groups of the same category cannot bear the same name.   Note — Previous use of a name in zoölogy does not preclude its use in botany; but the proposal of such a name should be avoided. |
| 4. | The application of a name is determined by reference to its nomenclatorial type. |
* Part II: Canons.
Section I. Categories of Classification. :
| Canon | 1. | Connected or coherent groups of individuals are termed species. |
| Canon | 2. | Species are grouped into genera; genera into tribes; tribes into families; families into orders; orders into classes; classes into divisions. |
| Canon | 3. | When additional categories are necessary for the convenient presentation of relationships, they are to be obtained by the recognition of intermediate groups, the names of which are formed by prefixing sub- to the names of the above principal categories. |
| | | Examples. — Subspecies, subgenus, subfamily, suborder. |
| Canon | 4. | Other terms, such as group, section, series, and branch, may be used for more convenient temporary arrangement under the above categories, but their names are to have no validity in formal taxonomy. |
| | | Note. — The term variety is relegated to horticultural usage. |
| Section II. Formation of Names. |||
| Canon | 5. | Specific and subspecific names consist of Latin or Latinized adjectives or substantives, the latter being either nominatives in apposition or genitives. |
| | | Examples. — Hookerianus; europaeus; vulgaris; heterophyllus; malvicola; Tulipifera; Tuna; Engelmanni; Sonorae; Trifolii. |
| Canon | 6. | Generic and subgeneric names consist of Latin or Latinized substantives, or equivalent terms. |
| | | Examples. — Rosa; Convolvulus; Hedysarum; Bartramia; Liquiadambar; Couroupita; Tsuga; Gloriosa; Impatiens; Manihot |
| Canon | 7. | Names for subtribes, orders, and intervening groups, are formed from names of component genera. |
| | (a) | For names of tribes add -eae, of families -aceae, of orders -ales, to the stem of the generic name. |
| | | Examples. — Roseae; Rosaceae; Rosales. |
| | (b) | For names of subtribes add -anae, of subfamilies -atae, of suborders -ares, to the stem of the generic name. |
| | | Examples. — Rosanae; Rosatae; Rosares. |
| Canon | 8. | Names for subclasses and higher groups consist of plural Latin or Latinized substantives. |
| | | Examples. — Monocotyledones; Angiospermae; Pteridophyta. |
| Section III. Publication of Names. |||
| Canon | 9. | A specific or subspecific name is published when it has been printed and distributed with a description (or in palaeobotany a figure), or with a reference to a previously published description. |
| | | Examples. — Coursetia arhorea Griseb. Fl. Brit. W. Ind. 183 (1859), is published with a description;Cynanchum nivale Nym. Syll. Fl. Eur. 108 (1855) is published with a reference to the previously described Vincetoxicum nivale Bois. & Heldr.;Pterospermites Whitei Ward, Ann. Rep. U. S. Geol. Surv. 6 : 556. pl. 56, f. 5, 6 (1885), a fossil species, is published with a figure, but without a description. |
| | (a) | In the transfer of a species from one genus to another, the original specific name is retained, unless the resulting binominal has been previously published. |
| | | Examples. — Bromus giganeus L. Sp. Pl. 77, is Festuca gigantea (L.) Vill. Hist. Pl. Dauph. 2: 110 (1787);Arum triphyllum L. Sp. Pl. 965, is to be known as Arisaema triphyllum ( L.) Torr. Fl. N.Y. 2: 239 (1843), not as Arisaema atrorubens Blume, Rumphia 1: 97 (1835); Laurus Sassafras L. Sp. Pl. 371, is to be known as Sassafras Sassafras (L.) Karst. Deutsch. Fl. 505 (1881), not as Sassafras officinale Nees & Eberm. Handb. Med.-pharm. Bot. 2: 418 (1831);however, Schoenus pusillus Sw. Nov. Gen. & Sp. PI. 20 (1788), when transferred to Rynchospora, is not to be known as Rynchospora pusilla (Sw.) Griseb. Kar. 123 (1857), because prior to 1857 the same binomial had been used for another species, Rynchospora pusilla Chapm. (1849). |
| Canon | 10. | A generic or subgeneric name is published when it has been printed and distributed (1) with a generic or specific description (or in palaeobotany a figure) and a binomial specific name, or (2) with a generic and specific name and the citation of a previously published description, or (3) with a reference to a specific description, which is associable by citation with a previously published binomial species. |
| | | Examples. — Pachysandra Michx. Fl. Bor. Am. 2: 177 (1803), is published with a generic and specific description and a binomial specific name; Brasenia Schreb. ex Gmel. Syst. 2: 853 (1791), is published with a generic description and a binomial specific name; Silphium L. Sp. Pl. 919 (1753), is published with a specific description and a binomial specific name; Poacites Schloth. Petrefact. 416, pi. 26, f. 1, 2 (1820), a fossil genus, is published with figures and a binomial specific name, but without a description; Nyssa L. Sp. Pl. 1058 (1753), is published with a generic and specific name and the citation of previously published descriptions; Dryopteris Adans. Fam. Pl. 2: 20 (1763), is published with a reference to a specific description associable by citation with the previously published Polypodium Filix-mas L. Sp. Pl. 1090 (1753), inasmuch as both Adanson and Linnaeus cite Filix mas of Fuchs. |
| Canon | 11. | Names of subtribes, orders, and intervening groups are published when they have been printed and distributed with direct or indirect citations of component genera. |
| | | Examples. — Moraceae Lindl. Veg. Kingd. 266 (1847), is pablished with the citation of component genera; Ophioglossales Engler, Syll. ed. 2, 63 (1898), is pablished with the citation of component genera |
| Canon | 12. | A name is not published by its citation in synonymy, or by incidental mention. |
| | | Examples. — Echeveria spicata, cited by De Candolle, Prodr. 3: 349 (1828) as a synonym of Fouquieria formosa, is not published and does not invalidate Echiveria DC. published on page 401 of the same volume; Arostichum Plumieri "Desv. herb." cited a a synonym of A. viscosum in Fée, Mem. Fam. Foug. 2: 46 (1845), is not published and does not invalidate Arostichum Plumieri Fée, published as a species on page 50 of the same work; Hormisus opuntioides Targ., cited by Bertoioni, Amoen. Ital. 316 (1819), as a synonym of Fucus Sertelara Bertol. ( ==  Halimeda Tuna), is not thereby published. |
| Canon | 13. | Of names published in the same work and at the same time, those having precedence of position are to be regarded as having priority. |
| | | Examples. — Alsine L. Sp. Pl. 272, is to be regarded as having priority over Sellaria L. Sp. Pl. 421;Aira spicata L. Sp. Pl. 63, is to be regarded as having priority over Aira spicata L. Sp. Pl. 64; Hibiscus Moschutos L. Sp. Pl. 693, is to be regarded as having priority over H. palustris, which it precedes on the same page. |
| Section IV. Application of Names. |||
| Canon | 14. | The nomenclatorial type of a species or subspecies is the specimen to which the describer originally applied the name in publication. |
| | | Examples. — Polypodium marginale L. Sp. Pl. 1091 is typified by the designation of a specimen collected in Canada by Kalm; Stachys arenicola Britton, Man. 792 (1901), is typified by the designation of a specimen from Staten Island, New York; Carex intumescens Fernaldii Bailey, Bull. Torrey Club 20: 418 (1893), is typified by a specimen collected at Cedar Swamp, Aroostook County, Maine, by M. L. Fernald. |
| | (a) | When more than one specimen was originally cited, the type or group of specimens in which the type is included may be indicated by the derivation of the name from that of the collector, locality or host. |
| | | Examples. — Eriogonum Porteri Small, Bull. Torrey Club 25: 41 (1898), is based on several specimens, of which the one collected by T. C. Porter is the type; Gaillardia arizonica A. Cray, Syn. Fl. N. Am. 1²: 353 (1884), is based on several specimens, of which the one collected by Palmer in Arizona is the type; Cuscuta Cephalanthi Engelm. Am Jour. Sci. 43: 336 (1842), is based on specimens from several hosts, of which the one from Cephalanthus is the type. |
| | (b) | Among specimens equally eligible, the type is that first figured with the original description, or in default of a figure the first mentioned. |
| | | Examples. — Calyptridium roseum S. Wats. Bot. Kings Exp. 44. pl. 6, f. 6-8 (1871), is based on at least three specimens, of which the one figured is the type; Arnica cordifolia Hook. Fl. Bor. Am. 1: 331 (1833), is based on two specimens, neither of which is figured, and the one first mentioned, which was collected by Drummond in alpine woods of the Rocky Mountains, is the type. |
| | (c) | In default of an original specimen, that represented by the identifiable figure or (in default of a figure) description first cited or subsequently published, serves as the type. |
| | | Examples. — Trillium sessile L. Sp. Pl. 340, is based on three citations, of which the second is thr type, being accompanied by a figure; Centaurea Scabiosa L. Sp. Pl. 913, is based on a number of citations, of which the first mentioned is the type, as no figures are cited. |
| Canon | 15. | The nomenclatorial type of a genus or subgenus is the species originally named or designated by the author of the name. If no species was designated, the type is the first binomial species in order eligible under the following provisions: |
| | (a) | The type is to be selected from a subgenus, section or other list of species originally designated as typical. The publication of a new generic name as an avowed substitute for an earlier invalid one does not change the type of a genus. |
| | | Examples. — Psilogramme Kuhn, Festschr. 50-Jähr. Jub. Königs. Realschule zu Berlin 332 (1882), is typified by the first-mentioned species of the second section Eupsilogramme, and not from species included in the first section Jamesonia, which is based on a generic name previously published; Phania DC. Prodr. 5: 114 (1826), is typified by P. multicaulis DC, the only species of the section Euphania; Guignardia Viala & Ravaz, Bull. Soc. Myc. Fr. 8: 63 (1892), which was substituted for Laestadia Auers. Hedwigia 8: 177 (1869) not Laestadia Kunth in Less. Syn. Compos. 203 (1832), is typified by Laestadia alnea (Fr.) Auers., which is the first of the three species given by Auerswald and accompanied by a citation of Fr. Scler. Suec. Exsic. no. 59, and not by Laestadia Bidwelli (Ellis) Viala & Ravaz, the only species mentioned by Viala & Ravaz at the time the substitution was made. |
| | (b) | A figured species is to be selected rather than an unfigured species in the same work.   In the absence of a figure, preference is to be given to the first species accompanied by the citation of a specimen in a regularly published series of exsiccatae.   In the case of genera adopted from prebinomial authors (with or without change of name), a species figured by the author from whom the genus is adopted should be selected. |
| | | Examples. — Lespedera Michx. Fl. Bor. Am. 2 : 70 (1803), is typified by L. procumbens Michx. loc. cit, pl. 39, the species first figured; Stigmatea Fr. Sum. Veg. Scand. 421 (1849), is typified by S. RobertianaFr , the fourth species, as there are no species figured and this is the first in the list accompanied by the citation of a specimen in published exsiccatae,Scler. Suec. Exsic. no. 423. |
| | (c) | The application to a genus of a former specific name of one of the included species, designates the type. |
| | | Examples. — Amsonia Walt. Fl. Car. 98 (1788), is typified by Tabernaemomtana Amsonia L., one of its two original species; SordariaCes. & DeN. Comm. Soc. Critt. Ital. i: 225 (1S63), is typified by Sphaeria Sordaria Fr., one of its twelve original species. |
| | (d) | Where economic or indigenous species are included in the same genus with foreign species, the type is to be selected from (1) the economic species or (2) those indigenous from the standpoint of the original author of the genus. |
| | | Examples. — Poa. L. Sp. Pl. 67 (l753). is typified by P pratensis L., the first of the economic species; Sanguisorba L. Sp. Fl. 116 (1753). is typified by S. offcinalis. the species indigenous from the standpoint of the author |
| | (e) | The types of genera adopted through citations of nonbinomial literature (with or without change of name), are to be selected from those of the original species which receive names in the first binomial publication.   The genera of Linnaeus' Species Plantarum (1753) are to be typified through the citations given in his Genera Plantarum (1754). |
| | | Note. — The Species Plantarum contains no generic references, but the 1754 edition of the Genera Plantarum was evidently prepared at the same time and was in effect a complementary volume of the same work.   It accords much mere nearly than other editions with the treatment followed in the Species Plantarum, and thus makes it possible to retain more of the Linnaean generic names in their current application. |
| | | Examples. — ''Cypripedium L, Sp. Pl. 951, a genus adopted from Tournefort with a change of his name Calceolus is typified by Cypripedium Calceolus the only species common to both authors; Seseli L. Sp. PI. 259, a genus adopted from Boerhaave, is typified by the second species of Linnaeus, Seseli montanum, which is the first in Linnaeus of the species common to both authors; Silene L. Sp. PL 416, a genus adopted from Dillenius with a change of his name Viscago is typified by Silene anglica, the first in Linnaeus of the thirteen species figured by Dillenius; Fritillaria L. Sp. PI. 303, a genus adopted from Tournefort, is typified by the fifth species of Linnaeus, Fritillaria Mleleagris which is one of the three species included in Fritillaria by both authors, and is selected from these three because it is the one figured by Tournefort. |
| Section V. Rejection of Name |||
| Canon | 16. | A name is rejected when preoccupied (homonym). |
| | (a) | A specific name is a homonym when it has been published for another species under the same generic name. |
| | | Examples. — Acer saccharinum Wang, Amer. 36. pl. 2, f. 26 (1787), is a homonym of Acer saccharinum L. Sp. Pl. 1055 (1753); Vaccinium myrtilloides Hook. Fl. Bor. Am. 2 : 32 (1834), is a homonym of Vaccnium viyrtilloides Michx. Fl, Bor. Am. i : 234 ( 1803), and is rejected whether the latter species is regarded as distinct or not; Chrysopsis pilosa (Walt.) Britton, Mem. Torrey Club 5: 316 (1894), is a homonym of Chrysopsis pilosa Nutt. Jour. Acad. Nat. Sci, Phila. 7 : 66 (1834), and is to be rejected, notwithstanding the fact that Erigeron pilosum Walt, was published in 1788. |
| | (b) | A generic name is a homonym when previously published for another genus. |
| | | Examples. — |
| | (c) | Similar names are to be treated as homonyms only when they are mere variations in the spelling of the same word; or in the case of specific and subspecific names, when they differ only in adjective or genitive termination. |
| | | Examples. — |
| Canon | 17. | A name is rejected when there is an older valid name based on another member of the same group (metonym). |
| | | Examples. — |
| Canon | 18. | A name is rejected when there is an older valid name based on he same type (typonym). |
| | | Examples. — |
| Canon | 19. | A name is rejected when the natural group to which it applies is undetermined (hyponym). |
| | (a) | A specific or subspecific name is a hyponym when it has not been connected with a description, identifiable by diagnostic characters or by reference to a type specimen, figure or locality. |
| | | Examples. — |
| | (b) | A generic or subgeneric name is a hyponym, when it is not associable, at least by specific citation, with a binomial species previously or simultaneously published; or when its type species is not indentified. |
| | | Examples. — |
* Part III: Orthography and Citation.
Section I. Orthography. :
| 1. | The original orthography of names is to be maintained, except in the following cases; the change not to affect priority. | The original orthography of names is to be maintained, except in the following cases; the change not to affect priority. |
| | (a) | Manifest typographical errors may be corrected. |
| | | Examples. — |
| | (b) | Adjectival names of species and subspecies agree in gender with the generic name with which they are associated. |
| | | Examples. — |
| | (c) | Generic names derived from personal names should be feminine, and if originally of other forms should be corrected. |
| | | Examples. — |
| | (d) | In the case of names proposed in works in which v and j were used as vowels or u and i as consonants they should be corrected to agree with modern usage. |
| | | Examples. — |
| 2. | Generic names should be written with initial capital letters. | Generic names should be written with initial capital letters. |
| | Examples. — | Examples. — |
| 3. | If capital letters are to be used for specific names they should be employed only for substantives and for adjectives derived from personal names. | If capital letters are to be used for specific names they should be employed only for substantives and for adjectives derived from personal names. |
| | Examples. — | Examples. — |
| 4. | The publication of names of bilingual derivation should be avoided, but published names are not to be rejected on account of such derivation. | The publication of names of bilingual derivation should be avoided, but published names are not to be rejected on account of such derivation. |
| | Examples. — Liquidambar is Latin-Arabic; Fimbristylis is Latin-Greek; Actiniceps is Greek-Latin. | Examples. — Liquidambar is Latin-Arabic; Fimbristylis is Latin-Greek; Actiniceps is Greek-Latin. |
| 5. | The names of hybrids may be written as follows: | The names of hybrids may be written as follows: |
| | (a) | A hybrid may be named by placing the names of the parent species or subspecies in alphabetical order, connected by the sign ×; but in hybrids experimentally produced, or in which the sex of the parents is known, the female parent is to be written first, and the sex indicated by the signs ?, ?; |
| | | Examples. — Carex debilis × virescens ;  Digitalis lutea ? × purpurea ?. |
| | (b) | A hybrid may be named when desirable like a species or subspecies, provided the binomial or trinomial is preceded by the sign ×, designating it as a hybrid. |
| | | Example. — × Salix capreola Kern. |
| | (c) | A hybrid between species of different genera may be named by attaching the specific name to the generic name of the female parent, or, if the sex of the parents is unknown, to the generic name coming first in alphabetical order. |
| | | Example. — × Ammophila baltica Link ==  Ammophila arenaria × Calamagrostis Epigeios. |
| | (d) | A hybrid derived from parents one or both of which are of hybrid origin, may be named by including the name of the hybrid parent in parentheses. |
| | | Example. — Salix (aurita × repens) × cinerea. |
| | (e) | Preponderance of one parent over the other may be designated by the signs >, <. |
| | | Examples. — Mentha longifolia > × rotundifolia ;  Mentha longifolia × < rotundifolia. |