Results from phylogenetic analysis of nuclear rDNA internal transcribed spacer (ITS) sequences from a worldwide sample of Sanicula indicate that Hawaiian sanicles (Sanicula sect. Sandwicenses) constitute a monophyletic group that descended from a western North American ancestor in Sanicula sect. Sanicoria, a paraphyletic assemblage of mostly Californian species. A monophyletic group comprising representatives of all 15 species of S. sect. Sanicoria and the three sampled species of S. sect. Sandwicenses was resolved in all maximally parsimonious trees, rooted with sequences from species of Astrantia and Eryngium. All sequences sampled from eastern North American, European, and Asian species of Sanicula fell outside the ITS clade comprising S. sect. Sanicoria and S. sect. Sandwicenses. A lineage comprising the Hawaiian taxa and three species endemic to coastal or nearcoastal habitats in western North America (Sanicula arctopoides, Sanicula arguta, and Sanicula laciniata) is diagnosed by nucleotide substitutions and a 24-bp deletion in ITS2. The hooked fruits in Sanicula lead us to conclude that the ancestor of Hawaiian sanicles arrived from North America by external bird dispersal; similar transport has been hypothesized for the North American tarweed ancestor of the Hawaiian silversword alliance (Asteraceae). Two additional long-distance dispersal events involving members of S. sect. Sanicoria can be concluded from the ITS phylogeny: dispersal of Sanicula crassicaulis and Sanicula graveolens from western North America to southern South America.The volcanic history, extreme geographic isolation, and disharmonic biota of the Hawaiian archipelago demonstrate that terrestrial life in the islands must have arrived by long-distance dispersal (1). Among plants, the approximately 966 species of indigenous Hawaiian angiosperms (89% endemic) have been estimated to stem from 272 to 282 natural introductions to the islands (2). On the basis of comparative floristics, Fosberg (3) hypothesized that most natural introductions of Hawaiian flowering plants were from southeast Asian source areas. Directionality of prevailing air currents, occurrence of intermediary ''stepping-stone'' islands, and climatic similarities between the Hawaiian archipelago and tropical areas to the west and southwest of the islands accord with Fosberg's estimate.A minority (about 18%) of ancestral Hawaiian plant colonists are thought to have dispersed from the Americas (3), despite unfavorable prevailing winds and water currents. Plant dispersal across the unbroken 3,900-km oceanic barrier between temperate western North America and the Hawaiian Islands appears to have been exceedingly rare. Molecular phylogenetic evidence of a California tarweed (Madia͞ Raillardiopsis) ancestry of the Hawaiian silversword alliance (Argyroxiphium, Dubautia, Wilkesia) provides one unequivocal example of such dispersal in the sunflower family (4-6). In this paper, we provide phylogenetic evidence from nuclear ribosomal DNA internal transcribed spacer (ITS) sequenc...
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. International Association for Plant Taxonomy (IAPT) is collaborating with JSTOR to digitize, preserve and extend access to Taxon.In addressing the seventh annual meeting of the Botanical Society of America, Benjamin Lincoln Robinson stated: "An accurate, lucid and complete classification of plants is... the only secure basis upon which botany as a whole can rest. What is the present strength of this all-important foundation? Is it built upon rational principles? Should we build on or tear down and reconstruct? Is it nearing completion or does it represent as yet only the earliest stages of the desired structure?" (1901, p. 2). These questions, although we might now word them a little differently, seem as germane today as they were sixty-three years ago. I. THE CONTINUING NEED Taxonomy is a lonely voice speaking on behalf of an interest in diversity in biology,where all other forces seem to be emphasizing the common denominators. In the United States, at least, the submergence of botany, bacteriology, and zoology into a broadly defined but narrowly oriented biology is going on at an increasing tempo, with a resulting stress on those features that are common to all or most organisms, and a deliberdte setting aside as of only secondary if any importance the so-called "details" of multicellular organisms. Some extremists would tell us that Darwinian evolution is regarded as "proven" and no longer of central interest to biology. Organisms are viewed merely as relatively uninteresting containers within which interesting physico-chemical processes are taking place, and only the latter are deemed worthy of serious study. In short, this trend toward "reductionism" has gone to such ridiculous extremes that we are probably about to witness the swing of the pendulum of interest in some other and as yet unperceived direction.Taxonomy, the first aspect of plant science to be pursued, has been traditionally associated with exploration in the field coupled with cultivation in the garden and study in the herbarium and library. Many otherwise informed persons assume that the exploratory phase of botany is essentially complete; this assumption is, of course, an entirely erroneous one. Keck (1959, p. 77) has recently estimated that "we shall not be through with our inventory in fifty years... my hunch is that we shall know the temperate floras of the world rather thoroughly in another 30 or 40 years, and that it will be at least twice as long before we can begin to think we know the tropical * Summation lecture of a symposium on the Broadening Basis of Classification, under the auspices of the Systematic Section at the Xth International Botanical Congress at Edinburgh, 7 August 1964. The writer is g...
Chromosome numbers are reported for nearly 300 collections of Umbelliferae. Of these, 150 representing “new” or variant counts are figured. Karyotypes of fifteen of the genera included have apparently not been documented before.
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