| Summary: | Thesis (Ph.D.) -- Memorial University of Newfoundland, 1973. Biology Bibliography : leaves 167-172 A consideration of the taxonomy of Ranunculus gmelinii DC., R. hyper- boreus Rottb,, R. eschsoholtzii Schlect., R. pedatifidus J.E. Smith, R. pygmaeus Wahl,, R. nivalis L., and R. sulphureus Sol. is presented. The role of phenotypic plasticity is indicated as a factor contributing to the range of morphological variation in these species and to the confusion found in their taxonomy. The present work, by a re-examination of representative material collected throughout the North American range of the species, and the use of controlled growth conditions, has suggested new limits for some of the species. This has resulted in modifications of the descriptions of the species and/or the reduction of taxa to synonymy. -- The following are suggested to designate North American representatives of the species. Ranunculus gmelinii DC, R. hyperboreus Rottb., R. eschsoholtzii Schlect. var. eschscholtzii (for Alberta and north), R. pedatifidus J.E. Smith var. leiocarpus Fern., R. pygmaeus Wahl., R. nivalis L., and R. Sulphureus Sol. The following have been reduced to synonymy: R. hyperboreus Rottb. var. turquetillanus Polunin (synonym of R. gmelinii), R. natans C.A. Mey var. intertextus (Green) L. Benson (synonym of R. hyperboreus), R. pedatifidus J.E. Smith var. afflnis (R. Br.) L. Benson, R. pygmaeus Wahl. var. langianus Nathorst., and R. sulphureus Sol, var. intercedens Hult. -- The chromosome numbers for specimens of the species included in the work and some other species of Ranunculus, each from several localities, have been determined. A technique for staining Ranunculus chromosomes has been developed in this study. -- The usefulness of chemotaxonomy in providing characters has been studied and it has been found that secondary metabolic products; such as flavonoids and phenolics, are not suitable. -- A discussion of the status of R. gelidus Kar. & Kir, and R. cymbal- aria Pursh var. alpinus Hook, has been included.
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