Honors Program Theses


Open Access Honors Program Thesis

First Advisor

Steven L. O'Kane, Jr.




Physaria is a recent and rapidly evolving genus of plants in the Brassicaceae family. Particularly problematic are the taxa in the “old” Physaria sensu stricto found in Wyoming, characterized by highly inflated, didymous fruits. Due to the plants in this group being of recent origin, the relationships among them are unknown. This study examined several samples from each taxon in a preliminary study of the taxonomy of these species. The resulting phylogenies were analyzed to determine relatedness among the species. By looking at gene regions, sections on the genomic sequence, it is possible to determine how these various plants are related.

The hopes of this study were to solve remaining taxonomic problems among the Physaria group, specifically what makes up 'old' Physaria. For example, are the subspecies of Physaria saximontana and Physaria didymocarpa really distinct?; do specimens with elongating caudices represent new taxa; does Physaria vitulifera grow in Wyoming? The relatedness among the species of 'old' Physaria were to be determined, as well as whether the species in this group are where they belong and what the monophyletic groups within 'old' Physaria are. It is important to understand the relationships among these species due to their recent and rapid origin

Year of Submission



Department of Biology

University Honors Designation

A thesis submitted in partial fulfillment of the requirements for the designation University Honors

Date Original


Object Description

1 PDF file (36 pages)



File Format


Included in

Botany Commons