Showing papers by "Michael F. Fay published in 1998"

An ordinal classification for the families of flowering plants

Abstract: Recent cladistic analyses are revealing the phylogeny of flowering plants in increasing detail, and there is support for the monophyly of many major groups above the family level. With many elements of the major branching sequence of phylogeny established

A phylogenetic analysis of Rhamnaceae using rbcL and trnL-F plastid DNA sequences.

Abstract: Previous tribal classifications of Rhamnaceae have been based on fruit characters, resulting in the delimitation of large and otherwise heterogeneous groups. We evaluated the most recent classification with DNA sequences of two regions of the plastid genome, rbcL and trnL-F, from 42 genera of Rhamnaceae and representatives of the related families Elaeagnaceae, Barbeyaceae, Dirachmaceae, Urticaceae, Ulmaceae, Moraceae, and Rosaceae. The trnL-F trees have higher consistency and retention indices than the rbcL trees, and patterns of change in rbcL and trnL-F are compared. The closest relatives of Rhamnaceae are Dirachmaceae and Barbeyaceae, followed by the urticalean families. The plastid trees support the monophyly of the family and provide the basis for a new tribal classification. Three strongly supported clades are identified, but morphological characters could not be found to underpin a formal taxonomic description of these three clades as subfamilies. We therefore only recognize groups that are also defined by morphological characters. The biogeography of Rhamnaceae is discussed with reference to the molecular trees.

Simultaneous parsimony jackknife analysis of 2538 rbcL DNA sequences reveals support for major clades of green plants, land plants, seed plants and flowering plants

Abstract: The ever-larger data matrices resulting from continuing improvements in DNA sequencing techniques require faster and more efficient methods of phylogenetic analysis. Here we explore a promising new method, parsimony jackknifing, by analyzing a matrix comprising 2538 sequences of the chloroplast generbcL. The sequences included cover a broad taxonomic range, from cyanobacteria to flowering plants. Several parsimony jackknife analyses were performed, both with and without branch-swapping and multiple random addition sequences: 1) including all positions; 2) including only first and second codon positions; 3) including only third positions; and 4) using only transversions. The best resolution was obtained using all positions. Removal of third positions or transitions led to massive loss of resolution, although using only transversions somewhat improved basal resolution. While branch-swapping improved both resolution and the support found for several groups, most of the groups could be recovered by faster simple analyses. Designed to eliminate groups poorly supported by the data, parsimony jackknifing recognizes 1400 groups on the basis of allrbcL positions. These include major taxa such as green plants, land plants, flowering plants, monocots and eudicots. We include appendices of supported angiosperm families, as well as larger groups.

Plastid rbcL sequence data indicate a close affinity between Diegodendron and Bixa

Abstract: Summary Diegodendron humbertii Capuron (Diegodendraceae Capuron) is endemic to Madagascar. The family is monospecific, and whereas various affinities have been suggested, its phylo- genetic position has remained unclear. Analysis of rbcL sequence data indicates a close re- lationship to Bixa. Together these taxa form a monophyletic group with a somewhat more distant relationship to other groups of Malvales s.l. including Cochlospermaceae. Cochlo- spermaceae (Cochlospermum and Amoreuxia) should be maintained as a family distinct from Bixaceae but if Bixaceae are expanded to include Cochlospermaceae they should also include Diegodendron. DNA extraction from herbarium specimens, involving modifications to the standard extraction and amplification techniques, is described.

Systematics of Plumbaginaceae based upon cladistic analysis of rbcL sequence data

Abstract: The monophyly and phylogenetic relationships of Plumbaginaceae (sensu Cronquist) were evaluated using parsimony analysis of nucleotide sequences of the plastid gene rbcL. Analysis of 42 taxa, including 18 species of Plumbaginaceae, placed this family as a strongly supported monophyletic group sis- ter to Polygonaceae and in the same clade as Simmondsiaceae, Nepenthaceae, Droseraceae and Caryophyl- lales. Within Plumbaginaceae, two well supported groups are present, corresponding to subfamilies Plumbaginoideae and Staticoideae. These groups have been regarded as independent families by some authors, and anatomical, morphological and biochemical differences are well defined. The taxonomic status of each group is discussed.

Muntingiaceae, a new family of dicotyledons with malvalean affinities

Abstract: The family Muntingiaceae, here described, includes the Neotropical, monotypic genera Muntingia and Dicraspidia, and probably Neotessmannia, which have previously been included in Elaeocarpaceae, Tiliaceae, or Flacourtiaceae. Morphological data discussed here and molecular data published elsewhere indicate that none of these families can be regarded as closely related to these genera. Muntingiaceae belong to a clade that comprises core Malvales (Sterculiaceae, Tiliaceae, Bombacaceae, and Malvaceae) and several other families. Within this alliance, relationships are presently unresolved.

Family relationships of the enigmatic rosid genera Barbeya and Dirachma from the Horn of Africa region

Abstract: Barbeya is a monotypic genus in the Horn of Africa and adjacent parts of Arabia. It is usually treated as the familyBarbeyaceae and regarded as an aberrant member ofUrticales. Dirachma, with one species on Socotra and one in Somalia, is usually treated as the familyDirachmaceae, inGeraniales, but a position inMalvales has also been suggested. Analyses of molecular data, from bothrbcL andtrnL-F, indicate thatBarbeya andDirachma are closely related inter se as well as toRhamnaceae andElaeagnaceae. In an analysis based on morphologyBarbeya groups withElaeagnaceae, andDirachma withRhamnaceae andUlmaceae. In a combined molecular and morphological analysisBarbeya is the sister group ofElaeagnaceae andDirachma is the sister group of the wholeBarbeya-Elaeagnaceae-Rhamnaceae clade. However, the support for these arrangements is weak and, rather than mergingBarbeyaceae withDirachmaceae as suggested by the molecular analysis or withElaeagnaceae as suggested by the morphological and combined analyses, it seems best to retain bothBarbeyaceae andDirachmaceae in their present circumscriptions, but in both cases in completely new positions in the angiosperm system. The results are compatible with a new circumscription ofRhamnales comprisingRhamnaceae, Elaeagnaceae, Dirachmaceae andBarbeyaceae.