Plant systematics is an ever-changing field that brings its past with it. I concentrate on dealing with that past from both an historical and a nomenclature perspective by concentrating on who, where and when plants were found in North America, and by compiling suprageneric names. The objective of my historical work is to provide concise information on the contributions of botanical collectors who gathered plants in North America from approximately 1600 until 1900, concentrating mainly on those who collected in eastern North America prior to 1780, and those who were in the West from 1780 onward. Suprageneric names are those scientific names given to plants at ranks above that of the genus. Prior to 1990 none of these names had been compiled or their correctness - in terms of the rules governing botanical nomenclature - evaluated. The objective of this effort is to compile all such names and make them available to other researchers.
Research interests include floristic studies in western North America (including endangered and threatened species), examination of historical specimens gathered in temperate North America, monographic studies on Polygonaceae subfam. Eriogonoideae, botanical nomenclature, history of botanical explorations in the New World, and a review of suprageneric nomenclature, including vascular plant family nomenclature and an evaluation of systems of classification at and above the family level. The most recent efforts involve a joint effort with Dr. Robert F. Thorne entitled "An updated classification of the Class Magnoliopsida ("Angiospermae")" published in Botanical Review (2007), a new version of the Angiosperm Phylogeny Group classification of flowering plants (APG-III, 2009), and a personal view of angiosperm classification entitled "An outline of a classification scheme for extant flowering plants" (2012).
"Botanical discoveries of Lewis and Clark on the Great Plains." Keynote speaker, The nature of Lewis & Clark on the Great Plains, Center for Great Plains Study, Lied Conference Center, Arbor Day Farm, Nebraska City, Nebraska; 2004
"Suprageneric names: Difficult under any code.", International Society for Phylogenetic Nomenclature, Yale University, New Haven, Connecticut; 2006
"Western Endemics: Eriogonum.", International Interim Rock Garden Plant Conference, Snowbird, Utah; 2006
Invited Presentations at Seminars:
"Medicinal plants of the Lewis and Clark expedition." Tai Sophia Institute, Laurel, Maryland; 2006
"Lewis and Clark: A look at the botanical exploits after the expedition." University of California, Berkeley; 2006.
"Lewis and Clark: A look at the botanical exploits after the expedition." Cornell University, Ithaca; 2007.
"Mark Catesby, artist and naturalist in colonial America." Rancho Santa Ana Botanic Garden, Claremont; 2008.
"Mark Catesby, artist and naturalist in colonial America." Boise State University, Boise; 2008.
"Catesby's enigma: Illustrations from 1730-1747 and the mystery of the Little Sparrow." Laboratory of Ornithology, Cornell University, Ithaca; 2009.
History of Systematic Botany – BIOPL 4450
This course is designed as a historical summary covering the development of botany, with an emphasis on the writings, discoveries and explorations from early human history to the twentieth century (1900). This is a foundation course which deals with the entire field of botany as practiced over time and as the information learned over the centuries was applied in our understanding of the identification, naming and classification of plants. It is presumed that when students take more specialized courses, the history of that specific field will be discussed in depth and is concentrated primarily on events from 1900 onward.