The classification and distribution of Ratibida columnifera var. columnifera Woot. and Standl. and R. columnifera var. pulcherrima (DC.) Woot. and Standl. are complex. Some floras list R. columnifera var. pulcherrima as a purple colored form or variety of the species while other authors refer to this taxon as a separate species of Ratibida. The purpose of this study is to clarify the taxonomic status of the two forms by determining and differences in morphology, distribution, taxonomy, and ecology.
An attempt has been made to determine the route by which R. columnifera columnifera and R. columnifera pulcherrima were distributed. After this was determined, a theory was formulated which correlated the pattern of distribution with the location of pure populations of the forms.
R. columnifera, New Mexico, Taxonomy, Morphology, Ecology, Botany
Level of Degree
UNM Biology Department
First Committee Member (Chair)
Raymond C. Jackson
Second Committee Member
William J. Koster
Third Committee Member
Howard J. Dittmer
Marshall, Walter W.. "A Distributional and Taxonomic Study of Ratibida Columnifera Var. Columnifera, Ratiba Columnifera Var. Pucherrima, and Their Hybrids in New Mexico." (1958). https://digitalrepository.unm.edu/biol_etds/196