摘要:

SummaryHedberg, O.: Ciadistics in taxonomic botany – master or servant? – Taxon 44: 3‐11. 1995. – ISSN 0040‐0262.Cladistics, a nowadays often computerized methodology for taxonomic research, is claimed by its proponents to be more advanced and less subjective than traditional evolutionary systematics. It offers a convenient method of combining factual character state distribution with assumptions on directions of evolutionary change, and of constructing hypothetic evolutionary trees. But its usefulness in taxonomic botany is hampered by difficulties in outgroup selection, frequency of parallelisms and reversals, and wide variation within taxa. Prudently used, cladistics may certainly be a useful tool to botanical taxonomists, but if pursued as an independent computer game it may be harmful to taxonomy and to biology as a whole.

ISSN:0040-0262    

DOI:10.2307/1222672

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryPak, J.‐H.&Bremer, K.: Phylogeny and reclassification of the genusLapsana (Asteraceae: Lactuceae).– Taxon 44: 13‐21. 1995. – ISSN 0040‐0262.A cladistic analysis of 40 morphological, fruit anatomical, and chromosomal characters in the five species ofLapsanaand eleven other species of theLactuceae (Crepidinae)shows thatLapsanais polyphyletic. The genus is redefined to include only the European to S. W. AsianLapsana communisand its allied taxa usually treated as subspecies. The four E. Asian species formerly placed inLapsanaare transferred to a new genus,Lapsanastrum,and the new combinationsL. apogonoides, L. humile, L. takasei,andL. uncinatumare made.

ISSN:0040-0262    

DOI:10.2307/1222673

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryHill, K. D.: The genusCycas (Cycadacae)in the Indian region, with notes on the application and typification of the nameCycas circinalis.– Taxon 44: 23‐31. 1995. – ISSN 0040‐0262.Diagnostic features of the Indian cycads are discussed, and a key is presented to the cycads of the Indian region.Cycas circinalisis shown to be an Indian endemic species, with two varieties.

ISSN:0040-0262    

DOI:10.2307/1222674

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryJacobs, S. W. L., Everett, J.&Barkworth, M. E.: Clarification of morphological terms used in theStipeae (Gramineae),and a reassessment ofNassellain Australia. – Taxon 44: 33‐41. 1995. – ISSN 0040‐0262.Terms used for describing the apical regions of the lemma of theStipeaehave been used inconsistently in the past. Those terms are listed and defined, and recommendations made for consistent usage where either more than one term has been used for the same structure or the same term has been used for more than one structure.Nassellais accepted as a segregate genus ofStipabutS. caudataandS. brachychaeta,two species confused in the past, are excluded fromNassellaand are best placed inAchnatherum.

ISSN:0040-0262    

DOI:10.2307/1222675

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryMamay, S. H.: Reinstatement of the fossil nameRussellites(not a synonym ofYuania). – Taxon 44: 43‐51. 1995. – ISSN 0040‐0262.The Permian genusRussellites,first described from Texas, U.S.A., is now known from several localities in China. However,Yuania,the name of a dissimilar Chinese plant, has been misapplied consistently to the ChineseRussellites,thereby obscuring an important palaeo‐floristic link between North America and Asia. The taxonomic independence of the two genera is emphasized, and the appropriate nomenclatural adjustments are made.

ISSN:0040-0262    

DOI:10.2307/1222676

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryLuque, T., Ruiz, C., Avalos, J., Calderón, I. L.&Figueroa, M. E.: Detection and analysis of genetic variation inSalicornieae (Chenopodiaceae)using random amplified polymorphic DNA (RAPD) markers. – Taxon 44: 53‐63. 1995. – ISSN 0040‐0262.Representatives ofArthrocnemum, SalicorniaandSarcocorniawere analysed using RAPD. The methods used were optimized by testing different conditions of the parameters. The genetic characterization of the mentioned taxa proved possible, demonstrating the usefulness of RAPD techniques to determine generic limits in theSalicornieae.

ISSN:0040-0262    

DOI:10.2307/1222677

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryNorris, R. E.:Melanamansia glomerata,comb, nov., andAmansia rhodantha,two hitherto confused species of Indo‐PacificRhodophyceae.– Taxon 44: 65‐68. 1995. – ISSN 0040‐0262.Amansia glomerataC. Agardh had been reported from widespread localities in the Indo‐Pacific region, including Africa's east coast. Numerous plants from the Hawaiian Islands, from where the species, including the lectotype specimen, was originally described, were found to have pseudopericentral cells, a characteristic of the recently described genusMelanamansia.Transfer of this species to that genus is made. The specimens from the Natal coast of South Africa, previously identified asA. glomerata,do not have pseudopericentral cells and belong in the genusAmansia.They are correctly namedA. rhodantha,a species first described from Mauritius and previously merged withA. glomerata.The two species closely resemble one another in several superficial characters, but are genetically distinct owing to their basic anatomical differences.

ISSN:0040-0262    

DOI:10.2307/1222678

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryTardif, B.&Hardy, J.: Assessing the relative contribution of variables in canonical discriminant analysis. – Taxon 44: 69‐76. 1995. – ISSN 0040‐0262.A procedure by which subsets of variables can be selected and their relative importance assessed in canonical discriminant analysis (CDA) is discussed. It is apparent from a review of the literature that only the standardized coefficients can be used for this purpose. However, an example relative to morphological variation of chives (Allium schœnoprasumL.) in eastern North America indicates that it would be hazardous, at least with small sample size, to select variables by the magnitude of their standardized coefficients alone, considering their exceeding instability when different sets of observations are included in the analysis. We argue that selection of variables, to be conducted with confidence, should be based upon t‐values associated with jackknife standardized coefficients.

ISSN:0040-0262    

DOI:10.2307/1222679

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummarySang, T.: New measurements of distribution of homoplasy and reliability of parsimonious cladograms. – Taxon 44: 77‐82. 1995. – ISSN 0040‐0262.Levels of homoplasy, measured by consistency index (CI) or retention index (RI), have been commonly used as indicators of reliability of parsimonious cladograms. Less attention has been paid to distribution of homoplasy which, however, may be another important parameter for estimating the reliability of cladograms. Average unit character consistency (AUCC), measuring distribution of homoplasy among the characters on parsimonious cladograms, is defined as the average of total unit character consistencies. When cladograms with the same CI are compared, the one with the largest AUCC also has the most asymmetric distribution of homoplasy, i.e., it is compatible with the largest portion of the characters, and homoplasy is concentrated in the smallest portion of cladistically unreliable or fast evolved characters of this cladogram. Homoplasy distribution index (HDI) is defined as the difference between the AUCC and CI, and can be used to compare distribution of homoplasy among cladograms with similar levels of homoplasy. A new measurement of the reliability of parsimonious cladograms, homoplasy distribution ratio (HDR), is defined as the ratio of the HDI to the homoplasy index (HI).

ISSN:0040-0262    

DOI:10.2307/1222680

出版商:Wiley    

年代:2019

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1222681

出版商:Wiley    

年代:2019

数据来源: WILEY