Evolution and classification of Asters, Goldenasters and Goldenrods (Fam. Compositae) and phylogeny of the Tribe Astereae. Phytogeography, multivariate morphometrics, cytotaxonomy and chemosystematics used to resolve evolutionary histories. Cytogeography of polyploids.

Nomenclature and typification of asters [Aster, Almutaster, Ampleaster, Biotia, Canadanthus, Diplactis, Doellingeria, Eucephalus, Eurybia, Heleastrum, Herrickia, Ionactis, Oclemena, Oreostemma, Sericocarpus, Symphyotrichum, Virgulus], Chrysopsis, Croptilon, Euthamia, Heterotheca, Pityopsis, Solidago and related taxa. Data maintained in *.ask files are available on request. [sample of nomenclatural data file]

Rare plants of Ontario: Asters and Goldenrods

Cytogenetics and cytogeography of the B Chromosomes of Xanthisma texanum