Abstract

Growing on dry saline soils throughout the Intermountain Region of the United States is a group of herbaceous, perennial species of Atriplex, including A. corrugata, A. cuneata, A. cuneata ssp. Introgressa, A. falcata, A. gardneri, A. tridentata, and A. welshii, designated as the Atriplex gardneri complex. Highly adaptive and competitive in the arid salt deserts, these species are valuable as forage for livestock and wildlife. Because of extensive variation present within this complex, considerable taxonomic confusion has resulted. To clarify taxonomic and phylogenetic relationships, selected populations and plants were analyzed morphologically, cytologically, ecologically, phenologically, and genetically. Polyploidy is common within most of the major taxons. The polyploid species show little morphological variation from that of their diploid ancestors. Diploids occupy well drained soils relatively low in salt and grow in isolated pockets; polyploid derivatives are more widely distributed, growing in the lower valley floors characterized by heavy soils of high sodium content.

Degree

PhD

College and Department

Life Sciences; Plant and Wildlife Sciences

Rights

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