摘要:

SummaryPreparatory to the use of volatile oils in systematic studies of Australian rainforest trees, the extent and systematic significance of seasonal variation in volatile oil composition were studied. Monthly samples were taken from eight trees of Lauraceae, representing six genera, over a period of 14 months; three of these trees wereLitsea leefeana. It was found that the patterns of variation shown by these trees over the sampling period varied between trees, and in each case appeared to be unrelated to any seasonal trend. An analysis of the variation within the three trees ofLitsea leefeanashowed only seven compounds varying significantly by month of sampling, while 65 varied significantly by tree. Of the former, only one compound exceeded 0.5%. These three trees remained clearly distinct in any multivariate analysis. Monthly samples taken from a tree ofSyzygium canicortex(Myrtaceae) over a period of 13 months were compared with single samples from nine other trees of this species. It was found that the variation within the one tree over the seasonal sampling period was less than the variation between trees. Thus it is concluded that seasonal variation presents no problems for sampling of Australian rainforest trees for volatile oil composition, and that samples can be taken at any time of the year.

ISSN:0040-0262    

DOI:10.2307/1220832

出版商:Wiley    

年代:1989

数据来源: WILEY

摘要:

SummaryPRECIS (Pretoria National Herbarium Computerized Information System) is designed to provide information about plants in southern Africa, a region that lacks a completed modern flora. The system now consists of four separate but linked components: Specimen, Taxon, Nomenclatural and Curatorial. The “PRECIS experiment” covers an estimated nine per cent of the world's plant species. It provides a broad and continuously up‐to‐date overview of the southern African flora as well as detailed information about particular species, specimens and localities. PRECIS results have wide applicability in taxonomic and vegetation studies, and could not have been obtained without computerization.

ISSN:0040-0262    

DOI:10.2307/1220833

出版商:Wiley    

年代:1989

数据来源: WILEY

摘要:

SummaryThe herbarium at the Catholic University of America, founded as early as 1895 and later known as the Langlois Herbarium at the Catholic University (LCU), Washington, D.C., was dispersed by sale in 1985 to 1986. The institutions which received portions of the LCU herbarium included CAN, CM, DOV, F, NA, TEX, US, WIS, and the Department of Botany, Howard University, Washington, D.C. (HUDC).

ISSN:0040-0262    

DOI:10.2307/1220834

出版商:Wiley    

年代:1989

数据来源: WILEY

摘要:

SummaryThrough the help of many librarians, the author was successful in locating in European and North American libraries the Lieferung wrappers to Eugen Johann Christoph Esper'sDie Pflanzenthiere(1788–1830) as well as to hisFortsetzungen der Pflanzenthiere(1794–1806). These wrappers permit the numerical and signature collation of these two important works. Because of the rarity of these Lieferung wrappers and the poor quality of the paper on which they were printed which, at present, is in various deplorable stages of deterioration, the Nachricht, the Verbesserungen, and the Druckfehler are quoted in their entirety. For each respective Lieferung the complete collation of pagination and the respective plates as issued therewith are given. The value of this information resides in the fact that the plates and their respective descriptions were not issued simultaneously; it is only through the Lieferung wrappers that the relation between the text and the plates can be determined with certainty.

ISSN:0040-0262    

DOI:10.2307/1220835

出版商:Wiley    

年代:1989

数据来源: WILEY

摘要:

SummaryThis paper reports on a method of extending species descriptions by incorporating information from the taxonomic hierarchy into a numerical classification of plant community types based on species. The basic species data are expanded to include information on higher taxonomic categories, such as genus, family, order, or class. Each stand is described by the presence, or abundance, of taxonomic categories but, unlike previous methods, only the necessary levels of the hierarchy are included. “Necessary” is here defined to be the highest level in the taxonomic hierarchy which uniquely identifies some specific taxon in the data set. If only a single member of an order is present in the data, then only taxonomic categories equal to or higher than, order are necessary to uniquely identify that taxon. Information on family, genus or species is simply redundant. Where several members of the same genus are present then all levels of the hierarchy will be recorded since they are all necessary for unique identification. Having obtained stand descriptions in terms of the taxonomic categories then classification can proceed normally using standard techniques. The method was applied to a small set of data, for which a variety of previous results was already available for comparison. The method appears to provide an effective means of extending species descriptions.

ISSN:0040-0262    

DOI:10.2307/1220836

出版商:Wiley    

年代:1989

数据来源: WILEY

摘要:

SummaryIt is emphasized that taxonomy concerns pattern and that attempts to apply temporal aspects to taxa, including species, are doomed to lead to unsolvable paradoxes. The temporal species concepts have serious impacts on biological theory as the recognition of taxa is confused with evolutionary processes. The choice of inclusiveness of any Linnean taxon is in principle arbitrary in each particular case.

ISSN:0040-0262    

DOI:10.2307/1220837

出版商:Wiley    

年代:1989

数据来源: WILEY

摘要:

SummaryThe series of five bibliographic indices for extant pollen compiled under the editorship of the late G. Thanikaimoni are analyzed with respect to instrumentation used in characterization of the angiosperm pollen wall. It is clear that scanning electron microscopy has become the most common means for examining pollen and that while the number of publications involving pollen morphology increases yearly, only a small number of genera have been studied with either scanning or transmission electron microscopes.

ISSN:0040-0262    

DOI:10.2307/1220838

出版商:Wiley    

年代:1989

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1220839

出版商:Wiley    

年代:1989

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1220840

出版商:Wiley    

年代:1989

数据来源: WILEY

ISSN:0040-0262    

DOI:10.1002/j.1996-8175.1989.tb04627.x

出版商:Wiley    

年代:1989

数据来源: WILEY