Nomina generica conservanda et rejicienda Spermatophytorum H.W. Rickett ET F.A. Stafleu 1959 - 1961 UTRECHT - NETHERLANDS Reprinted from Taxon, Official News Bulletin of the I.A-P.T. and published by the International Bureau for Plant Taxonomy and Nomenclature Reprinted from Taxon 1959—1961 as follows: I. from vol. 8(7): 213—243. 12 August 1959. II. from vol. 8(8): 256—274. 20 October 1959. 111. from vol. 8(9): 282—314. 21 December 1959. IV. from vol. 9(3): 67—86. 29 March 1960. V. from vol. 9(4); 111—124. 10 May 1960. VI. from vol. 9(5): 153—161. 30 June 1960. VII. from vol. 10(3): 70—91. 25 April 1961.* VIII. from vol. 10(4): 111—121. 2 June 1961.* l± from vol. 10(5): 132—149. 30 June 1961.* X. from vol. 10(6): 170—193. 30 August 1961. * Some minor corrections inserted in reprint. NOMINA GENERICA CONSERVANDA ET REJICIENDA SPERMATOPHYTORUM I*) H. W. Riekett (New York) and F. A. Stafleu (Utrecht) Pages 220-279 of the International Code of Botanical Nomenclature (1956) are occupied a list of conserved and of of The by rejected names genera Spermatophyta. origins and history of conservation have been discussed by Stafleu (Taxon 5: 85-95). As result of it became evident that the list is a his study no longer in harmony with current concepts of nomenclature and the rules for maintaining them. The of of the list desirability a general revision is obvious; such a revision was begun Stafleu several It an task for by years ago. proved, however, impossible one person achieve in the intervals between duties. to ordinary Consequently application was made by The International Association for Plant Taxonomy to the National Science Foundation for in furtherance of this The (Washington) a grant project. grant was awarded in the authors to work for early 1958, enabling present together some seven weeks in Holland and England, principally in the Institute of Systematic Botany of the University of Utrecht and the Botany Department of the British Museum this the (Natural History). During period we completed verification (begun Stafleu alone) of almost citation the and the of by every in list, evaluation every conservation and rejection in the light of the current rules of nomenclature. The in Utrecht and New final manuscript was prepared later, York; an additional con- authors ference of the was made possible by Stafleu’s visit to the United States in December, 1958. A proposal has been presented to the Ninth International Botanical Congress, to be held at Montreal in 1959, to replace the current list of conserved and rejected of of list based that which follows names genera Spermatophyta by a new on (see Synopsis of Proposals, Regnum Vegetabile 14: 79. 1959). Our sincere thanks are due to the officers and botanists of the several institutions have the whose facilities and cooperations we enj oyed, particularly to following: Dr. J. Lanjouw, Director, Institute of Systematic Botany, University of Utrecht. Dr. J. J. Swart, of the same Institute. Dr. H. J. Lam, Rijksherbarium, Leiden. Dr. R. Lorentz, Librarian, Teyler’s Stichting, Haarlem. 213 Mr. J. S. L. Gilmour, Director, University Botanic Garden, Cambridge. Mr. J. E. Dandy, Head, Botany Department, British Museum (Natural History). Mr. W. T. Stearn, of the same institution. Mr. R. Ross, of the same institution. Miss P. Edwards, Librarian, Botany Department, British Museum (Natural History). Dr. G. Taylor, Director, Royal Botanic Gardens, Kew. Mr. Ch. E. Hubbard, Keeper of the Herbarium, Royal Botanic Gardens, Kew. Mr. V. S. Summerhayes, The Herbarium, Royal Botanic Gardens, Kew. Mr. A. A. Bullock, of the same institution. Mr. N. Y. Sandwith, of the same institution. Dr. H. E. Moore, Bailey Hortorium, Ithaca. Dr. R. C. Rollins, Director, Gray Herbarium, Harvard University, Cambridge, Mass. Dr. A. C. Smith, Director, Natural History Museum, U.S. National Museum, Washington. Mrs. L. Schwarten, Librarian, Harvard University Herbarium. Miss E. Hall, The New York Botanical Garden. Dr. R. S. Cowan, Department of Botany, U.S. National Museum, Smithsonian In- stitution, Washington. several of the for the that in this Although reasons changes we propose publication have been discussed the Stafleu mentioned already at some length in paper by above, of the that fuller should be here. The remainder of we are opinion a survey given this introduction is devoted to this survey. 1. Errors and Mistakes The list of conservanda for that nomina et rejicienda Spermatophyta now appears the Code started the 1905. Since then been in was by Vienna congress of it has reprinted again and again (four editions of the Rules and two of the Code), and understandable that in several mistakes have in: it is this repeated reprinting crept of realize that erroneous citations, changes spelling, etc. We our list also contains such mistakes, but we hope to have eliminated more old ones than we have made new ones. In works such as this ultimate precision is hypothetical only. Another which be of lesser is the in the of certain item, may interest, inconsistency use have abbreviations of titles and the like to which various authors drawn our attention. We have tried to bring the list into accord with the rules and recommendations also in this respect, and particularly to make it consistent within itself. 2. The Effect of Changes in the Rules It is well known that the rules of nomenclature have been repeatedly changed since the Vienna This continual be attributed to a congress. changing can only partly certain wilfulness the of nomenclatural Most of the on part legislators. changes, direct result of the including all the important ones, have been a development of scientific plant taxonomy and of the growing tendency among all taxonomists to of nomenclature rather than adhere to some one system to competing systems or all. The number of taxonomists who the to no system at now consistently ignore international rules is small. The result of these tendencies has been that a very growing number of taxonomists have been actively engaged in perfecting the rules and of historical rather than in regulating our use works, adhering simply to unwritten tradition. A few examples will illustrate this development. The Absolute Rule. Before the of 1930 it a. Homonym Cambridge congress was later if the earlier This rule worked possible to use a homonym one was illegitimate. 214 well the quite in nineteenth but in the twentieth a oi century, growing group taxonomists became opposed to it. If they had adhered strictly to the requirement of for the earlier all would have well. “illegitimacy” homonym, perhaps gone This, since distinction made that between however, was impossible, no sharp was at time “correct” and earlier that but later “legitimate”. Many homonyms were legitimate taxonomic obstacle the of later synonyms were regarded as no to use a homonym; it is clear that confusion was inevitable, because the decision whether or not a later homonym was available became taxonomic (subjective) rather than objective. The rule rather “once a homonym always a homonym” or “once a later homonym, for in always illegitimate” (except conservation) was adopted at Cambridge 1930; this an end to what had become confused situation. put a very One of the results of this that that decision, however, was many names were in be later and therefore It the common use appeared to illegitimate homonyms. was the that such should be dealt express understanding at Cambridge congress cases with by conservation, and an impressive number of nomina conservanda was added to the list (see Kew Bull. 1935: 341-544). Another, more unexpected result of the adoption of the absolute homonym rule that several made the Under was conservations in past now became superfluous. the old that be system a name was a later homonym might available to replace a well-known but later the well-known taxonomic synonym; name could be saved only conservation. After 1930 the would be by competing name illegitimate anyhow because of the earlier homonym. Examples of this sort of superfluous conservation are; 3050 Dontostemon, 3122 Caylusea, 3753 Clianthus, 3810 Alysicarpus, 4077 Tod- dalia, 5600 Agonis, 5259 Amphirrox. An equally unexpected result of the introduction of the absolute homonym rule was that by the above-mentioned stream of new nomina conservanda a number of names were declared illegitimate that had hitherto been legitimate and that had competed with well-known other names for which conservation had been invoked. Such conservations now became superfluous. [It should be pointed out that a name rejected in favour of a later homonym becomes illegitimate (unavailable) under the Code, since distinct taxa cannot bear the It can never same name. replace any other name. See also 4a below.] An of such chain is the The 4297 example a of events following: name Securinega Commerson A. L. Jussieu ex (1789) is conserved over its taxonomic synonym Acidoton P. Browne is but when it (1756). Securinega a legitimate name competes with the earlier Acidoton the former would be the correct name for the taxon. Later, however, 4415 Acidoton Swartz (1788) was conserved over its earlier homonym Acidoton P. Browne (1756). This means that the latter is no longer available to and that this without conservation. replace Securinega name stands The of Weihea different. This case 5528 is slightly name was conserved over Richaeia Thouars for which it avowed Weihea (1806) was an synonym. was illegiti- since Richaeia itself 6254 mate on publication was legitimate. The conservation of Richea R. Brown Richaeia Thouars makes the latter (1810) over (1806) illegitimate, but this does not mean that Weihea is now available without conservation. Weihea ” when and was (Art.