Sul Ross State University Sul Ross State University

A. Michael Powell

Director and Curator, Sul Ross State University Herbarium (SRSC)

SR Cactus Garden located south of Lawrence Hall Contact Information:

Warnock Science Building 218
Sul Ross State University
P.O. Box 6064
Alpine, Texas 79832
(432) 837-8113 (Office)
(432) 837-8112 (Department of Biology)


  • Ph.D. 1963 The University of Texas at Austin
  • M.A. 1960 Sul Ross State University
  • B.S. 1960 Sul Ross State University
  • A.A. 1957 Howard County Junior College

Research Interests:

  • Plant Systematics, emphasizing field, morphological, cytological, cytogenetic, and artificial hybridization approaches.
  • Floristics of the northern Chihuahuan Desert Region, including Trans-Pecos Texas.
  • Cactaceae of Trans-Pecos Texas
  • Rare plants of Trans-Pecos Texas
  • Native plant horticulture
  • Economic plants for arid lands
  • Revegetation of disturbed habitats in the Chihuahuan Desert Region


  • Over 100 articles in professional journals
  • Books in print:


  • Regional, national, and international botanical and biological societies

  • Chihuahuan Desert Research Institute (CDRI), Board of Directors, Board of Scientists

Selected Courses (some taught in alternate years):

Fall Semester:
Native Plant Horticulture
Spring Semester:
Economic Botany
Cell Biology
Cacti and Succulents of the Southwest
Summer I:
Plant Taxonomy

Current Graduate Students:

Amy Causey (B.S., Sul Ross)
Thesis research: Biology of Opuntia davisii

Fran Pontasch (B.S., Texas A & M)
Thesis research: Identification of Potential Insect Vector Host Plants of the Pierce’s Disease Bacterium Xylella fastidiosa in the Trans-Pecos Region of Texas

Recent Graduate Students:

Jack Brady (B.S., Sul Ross)
Thesis research: A Biosystematic Study of the Opuntia kleiniae complex

Patrick Griffith (B.S., UT Austin)
Thesis research: Breeding Systems of and Natural Interspecific Hybridization in Opuntia of the Northern Chihuahuan Desert Region

Stacey Haynie (B.S., UT Austin)
Thesis research: Vegetative Analysis of the Fort Davis National Historic Site

Gretchen Kliem (B.S., TCU)
Thesis research: Pollination Ecology of the Opuntia macrocentra complex

General Botany Students, click here