摘要:

SummaryMaxted, N.: Towards defining a taxonomic revision methodology. ‐Taxon41: 653‐660. 1992. ‐ ISSN 0040‐0262.The process of undertaking a taxonomic revision is central to taxonomy. However, no clear definition of or established methodology for undertaking a revision exists. Current attempts to apply contemporary computer technology throughout taxonomy can only be successful when the process itself is clarified. The subject of taxonomic revisions is introduced and a working definition is provided. The processes that are normally included in a revision are discussed and these are incorporated into a simple paradigm that models revision activities. Adherence to the paradigm will encourage researchers to adopt a logical methodology, which will lead to revision products being more complete and comparable.

ISSN:0040-0262    

DOI:10.2307/1222391

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryCanne‐Hilliker, J. M: An emended description, chromosome counts, and a key to South AmericanGalinsoga (Asteraceae, Heliantheae). ‐ Taxon41: 661‐666. 1992. ‐ ISSN 0040‐0262.An emended description ofGalinsoga boliviensisis provided based on data from recent collections from the vicinity of Sucre, Bolivia. The species is one of two in the genus known to be hexaploid (n= 24). The chromosome number ofG. mandoniiis reported asn= 16. An updated key to South American species ofGalinsogais given.

ISSN:0040-0262    

DOI:10.2307/1222392

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryCuerrier, A., Barabé, D.&Brouillet, L.: Bessey and Engler: a numerical analysis of their classification of the flowering plants. ‐Taxon41: 667‐684. 1992. ‐ ISSN 0040‐0262.The classifications of Bessey and Engler were compared using the Mantel and Lapointe‐Legendre consensus tests. Even if real differences were noted in some of the dicta or principles underlying their systems, content of groups at the ordinal level was not statistically different. The main difference lies more in the hierarchical, topological structure of their classifications. Bessey's classification is less polytomous in the higher categories than Engler's. We hypothesize that Bessey was more concerned with the higher level, using a divisive approach to construct his classification, and Engler with the lower level, using an agglomerative or mixed approach. Our results show that Bessey's classification does not fully represent ‘an expression of a theory of evolution‘. Engler and Bessey appear to have used sequences of taxa to reflect their morphological progressions. The results of the numerical and historical analyses were in agreement. The former helped refining the results of the latter.Il faut commencer une étude par quelques propositions évidentes qui fixent les idées. Cela fait, en général, un travail ennuyeux; mais nous avons une grande chance: c'est que les évidences, dont il s'agit ici, ont été négligées.Jean Paulhan (1948)

ISSN:0040-0262    

DOI:10.2307/1222393

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummarySpooner, D. M.&Berg, R. G. van den: Species limits and hypotheses of hybridization ofSolanum berthaultiiHawkes andS. tarijenseHawkes: morphological data. ‐Taxon41: 685‐700. 1992. ‐ ISSN 0040‐0262.Solanum berthaultiiHawkes andS. tarijenseHawkes have been recognized as distinct species by all authors since their description in 1944. Some authors have considered them as sister species, but more recently they have been treated as unrelated species belonging to separate superseries. Hypotheses of species boundaries and hybridization have been examined using principal components analysis, stepwise discriminant analysis, canonical discriminant analysis, and one‐way analysis of variance. 25 morphological characters measured on four individuals from each of 84 living accessions from throughout their natural range were analysed. Extensive intra‐accession, intraspecific, and interspecific variability have been found in many characters, including those previously given great taxonomic weight. 9 characters show no statistically significant differences between species or putative interspecific hybrids. The remaining 16 characters show statistically significant differences between species and putative hybrids, but show so much variability that repeatable identifications of some accessions would require the use of population samples. The data suggest the possibility that the two species should be treated as one. Other currently‐recognized species withinS. sect.Petotamay need to be reevaluated for synonymy. The results also question the hypotheses of extensive hybridization, interpretation of series designations, and the phylogenetic interpretation of corolla shape at the superseries level inS. sect.Petota.

ISSN:0040-0262    

DOI:10.2307/1222394

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryRogstad, S. H.: Saturated NaCI‐CTAB solution as a means of field preservation of leaves for DNA analyses. ‐Taxon41: 701‐708. 1992. ‐ ISSN 0040‐0262.Details of a method for preserving leaves for subsequent DNA analyses using a solution that is saturated (obviating precise field weighing of chemicals) with both NaCl and CTAB are presented. Since the dry ingredients are easy to obtain and transport, the method can be utilized even at very remote sites. Results from fresh versus preserved leaves ofPodophyllum, Polyalthia(3 spp.), andTaraxacumdemonstrate that DNA suitable for restriction fragment analysis can be obtained from leaves that have been stored in the solution for up to one month at ambient temperatures and then frozen for over one year at ‐20°C (ultracold storage at ‐70°C is not necessary). Degradation of DNA with this new method appears to be less for some taxa than with previously proposed DNA extraction methods using dried leaves. Analyses of DNA from leaves collected at remote rain forest sites are demonstrated.

ISSN:0040-0262    

DOI:10.2307/1222395

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryDu Plessis, H.&Spies, J. J.: Chromosome numbers in the genusPentaschistis (Poaceae, Danthonieae). ‐ Taxon41: 709‐720. 1992. ‐ ISSN 0040‐0262.On the basis of a study of meiosis, new chromosome counts are reported for 7 of the 68 species of the genusPentaschistis. Two different basic chromosome numbers are present in the genus, i.e. 7 and 13. Polyploidy is frequently observed and B‐chromosomes are present in some species, and existing data summarised. First chromosome numbers are reported forP. argentea(n= 21),P. aureasubsp.aurea(n= 7),P. capillaris (n =7),P. curvifolia (n= 7),P. papillosa (n =7),P. tortuosa (n =7) andP. triseta (n= 7). Additionly two new ploidy levels, diploid and heptaploid, are described forP. eriostoma.

ISSN:0040-0262    

DOI:10.2307/1222396

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryFarjon, A.:Cathaya loehrii, a misnomer for a Pliocene conifer cone. ‐Taxon41: 721‐723. 1992. ‐ ISSN 0040‐0262.A fossil seed cone of a conifer(Pinaceae)from the Pliocene of Germany, first described underAbies, subsequently underKeteleeria, and since 1958 frequently referred to the new genusCathaya, is shown to belong to none of these genera. The combinationC. loehriidoes not appear to have been validly published.

ISSN:0040-0262    

DOI:10.2307/1222397

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryIsoviita, P.: Report of the Special Committee 3 on Lectotypification. ‐Taxon41: 725‐727. 1992. ‐ ISSN 0040‐0262.A general discussion is given of the background and work of the three Subcommittees comprising this Committee: 3A Lectotypification, 3B Retroactivity of Lectotypification and Illegitimacy, and 3C Lectotypification of Linnaean Generic Names.

ISSN:0040-0262    

DOI:10.2307/1222398

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryPhillips, S. M., Brummitt, R. K.&Molloy, B. P. J.: Problems of types with duplicate specimens. ‐Taxon41: 728‐730. 1992. ‐ ISSN 0040‐0262.The definitions of the various categories of types in theCodeare somewhat ambiguous, and have been interpreted in conflicting ways by different authors. In particular, problems have arisen where a single type collection cited in the protologue consists of a series of duplicates. When is lectotypification necessary? How should the term ‘syntype’ be interpreted? Amendments to the wording of theCodeare suggested with the aim of achieving uniformity of practice.

ISSN:0040-0262    

DOI:10.2307/1222399

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryHerendeen, P. S.:Podocarpium podocarpumcomb. nov., the correct name forPodogonium knorriiHeer, nom. illeg. (fossilFabaceae). ‐ Taxon41: 731‐736. 1992. ‐ ISSN 0040‐0262.A neotype is proposed forGleditsia podocarpaA. Braun, which is the basionym forPodocarpium podocarpum(A. Braun) Herendeen, a new combination that must replacePodogonium knorriiHeer, which is illegitimate.

ISSN:0040-0262    

DOI:10.2307/1222400

出版商:Wiley    

年代:2019

数据来源: WILEY