Indiana University Bloomington
Postdoctoral Fellow
Prairie View A&M University
Postdoctoral Researcher
Missouri Botanical Garden
Scientific Editor
New Mexico State University
Assistant Professor
UNAM Instituto de Biología
Electron Microscopist
Institute of Biology, UNAM
Research Assistant
New Mexico State University
Associate Professor and Herbarium Director
Facultad de Ciencias, UNAM.
Research Assistant
Conagua
Research Assistant
University of Missouri-Saint Louis
Universidad Nacional Autónoma de México
