Research active emeritus professor with interests in all aspects of plant taxonomy and systematics at and below the level of genus.
Research areas include floristics, population genetics/genomics, phylogeography, phylogenetics/genomics, morphometrics, niche modeling, hybridization, and polyploidy. Systematic techniques range from chromosome counts and flow cytometry to CAPs, microsatellites, and ddRADSeq. Genera under investigation are typically species rich, including Carex (Cyperaceae), with an emphasis on cryptic taxa and species of special concern, such as Carex scirpiformis, Penstemon degeneri, and Eutrema penlandii. Following are some research highlights from over the past 35 years.