One-hundred-year code déjà vu?

The approach to the next international botanical congress, to be held in Vienna in 2005, is curiously similar to that (100 years earlier) leading into the Vienna Congress of 1905. Entering the 1905 Vienna Congress, four competing codes were in use--"the De Candollean, the Kew, the Berlin, and the American" (Weatherby, 1949). A strong presence in the background at the 1905 congress was Otto Kuntze, with his penchant for name changes (Smith, 1957), potentially impacting nomenclatural stability. Issues considered at the 1905 congress were: the type method; the use of descriptive Latin; how strict priority should be, and relatedly, a proposal to conserve certain names. From the 1905 congress, the first set of internationally codified rules was established, which included acceptance of a list of conserved generic names (Nicolson, 2000). Competing codes were not eliminated as a result of the 1905 congress, however, but were reduced to two (Weatherby, 1949)-the International Rules (arising basically out of the Candollean system) and the American Code. Most European taxonomists were unwilling to accept the type method, the rigid views on priority, or the laxity toward the use of Latin, supported by the American contingent. Through conciliatory efforts, e.g., Hitchcock (1925), agreement on adopting the type method for the application of names, and on requiring Latin diagnoses for new taxa, was achieved in the Cambridge Congress in 1930; the Latin requirement did not actually take effect until 1 January, 1935. Botanical congresses since Cambridge, 1930, have not produced such major substantive changes in pursuant editions of the botanical code. In spite of rumblings after the Yokohama Congress, 1993, regarding adoption of name lists and the like, deliberations of the St. Louis Congress, 1999, led to little significant change in the code document. There has, thus, been a more than 70year period of relative code stability. However, as we approach the Vienna Congress, 2005, it appears that taxonomists will again be facing (much as in the Vienna Congress of 1905) the real possibility of the intrusion of several, potentially competitive codes and/or strongly conflicting ideas, each with respective advocates. The codes or putative codes which could significantly affect botanical nomenclature are: the International Code of Botanical Nomenclature (ICBN); the International Code of Nomenclature for Cultivated Plants (ICNCP; Trehane & al., 1995), this "cultivated code" not being competitive against the ICBN; the PhyloCode; and the BioCode. And, now waiting in the background is, not Otto Kuntze, but the seemingly ever-present urgings for adoption of vetted name lists (Hawksworth, 2000; McNeill, 2000). The specter of major alterations of the rules, looming again in 2005, as in 1905, pointedly reifies the popular expression, "the more things change, the more they stay the same". Of particular concern at this time are the implications of implementation of a "PhyloCode". The work of de Queiroz & Gauthier (1990, 1994), de Queiroz (1997) and Cantino & al. (1997) led to the perception of a need to translate phylogenetic principles directly into nomenclatural practice. Their methodology would apply names to clades, not ranks, and would provide phylogenetic "definitions" of such names (Stuessy, 2000, 2001, has questioned "name definition"). Concepts of phylogenetic nomenclature have been merged with, or melded into, the present push for rank-free classification and the PhyloCode (cf. Hibbett & Donoghue, 1998; Mishler, 2000; Langer, 2001); all of this is based on the belief that attempting to prosecute phylogenetic work under Linnaean (and Hennigian) classification may proliferate a cumbersome list of names according to rank, putatively anathema to phylogenetic progress; many such names, it is felt, would later have to be disbanded or changed. Though some workers are possibly loath to admit it, unwanted name changes now may relate to differing results obtained, on the same group of organisms, using different types of molecular data and/or different computational methodologies (cf. Daugbjerg & Andersen, 1997; Marshall, 1997; Maley & Marshall, 1998; Waddell & al., 1999). Precepts of phylogenetic nomenclature and rankless systems are embodied in the current internet posting of the developing PhyloCode (http://www.ohiou.edu/phylocode/). Text accompanying the PhyloCode states that it "may be used concurrently with existing codes based on Linnaean nomenclature", the implication being that the PhyloCode is a document which may offer taxonomists additional nomenclatural benefit. However, also stated is