Angelo State Natural History Collections: Herbarium Curator
Office: 127B Cavness
Phone: (325) 486-6656
Ph.D. Botany, University of Oklahoma, 1981
M.S. Biology, Angelo State University, 1976
B.S. Biology, Angelo State University, 1973
Primary Teaching Responsibilities
Principles of Biology(Biology 1480)
General Botany (Biology 2401)
Medical Botany (Biology 3305)
Plant Taxonomy (Biology 4435)
Phytogeography of Texas Endemics
Pollination Ecology/Reproductive Biology
My students and I are studying four rare plants.
- The Big Pod Bonamia (Bonamia ovalifolia, Convolvulaceae) historically had a range along the Rio Grande River, but is now known from only a few sites in Big Bend National Park. Working with Big Bend National Park, we studied the reproductive biology and pollination ecology and attempted to find additional populations. We hope to conduct additional investigations with this species in the near future.
- The Chisos Mountain Hedgehog Cactus (Echinocereus chisoensis) is a threatened cactus found only in Big Bend National Park. Our emphasis with this species is its pollination ecology and reproductive biology. Included in this study is an investigation of its floral attractants (i.e. floral reflectance patterns, nectar and pollen amino acids, caloric values of pollen, nectar carbohydrates) and comparisons with the attractants of other co-flowering cacti. Assisted by the Phoenix Desert Botanical Garden, we have studied the seed ecology and germination requirements. We are now helping Dr. Joe Sirotnak, Big Bend National Park, and Ms. Kathy Rice, Desert Botanical Garden with a reintroduction project.
- The Texas Poppy Mallow (Callirhoe scabriuscula, Malvaceae), an endangered plant, is restricted to four west-central Texas counties. My interest in this species is long-lived and over the course of several years, my students and I have investigated numerous aspects of this rare plant’s biology, including the pollination biology and reproductive biology, genetic heterogeneity of several populations, its seed bank and seed germination requirements, and its floral attractants. We are currently working with the Mitchell County Board of Economic Development, under the guidance of the U.S. Fish and Wildlife Service, on a reintroduction project.
- Recently, we added the Hill Country Wild Mercury (Argythamnia aphoroides [Ditaxis aphoroides], Euphorbiaceae) to our list of plants of interest. We are now concluding a two-year study of the pollination ecology and reproductive biology of this species at Camp Bowie for the Texas National Guard. During our investigation we discovered a sympatric population of Argythamnia simulans, another uncommon Edwards Plateau endemic. We plan to continue comparing the reproductive biology of the two species. We are also conducting a predictive mapping project at Camp Bowie for A. aphoroides.