Associate Professor, Earth System Science

Phone: (541) 552-6804
Office: (temporary) Trailer Hall 110
Email: jessup@sou.edu


Ph.D. (Botany), University of Michigan, Ann Arbor 1994
B.S. (Botany), University of Maryland, College Park 1977


Environmental Studies

  • Intro to Environmental Studies: Biological Science (ES 102)
  • Biodiversity (ES 379)
  • Science and Advocacy in Environmental Policy Debates (ES 383)
  • Ethnobotany and Cross-Cultural Communication (ES 384)
  • Biosphere, Ecology and Global Environmental Change (ES 479)


  • Plant Evolution and Systematics (Bi336)
  • Origins and Diversity of Land Plants (Bi432/532)
  • Algae, Fungi and Lichens (Bi436/536)
  • Plant Identification and Field Botany (Bi444/544)
  • Methods in Plant Systematics (Bi435/535)
  • Bryophytes (Bi442/542)
  • History and Philosophy of the Environmental Movement (Sc345)
  • Natural History of the Pacific Northwest (Bi532)
  • Senior Research in Ecology and Evolutionary Biology (Bi492)
  • Bryophytes and Lichens (Siskiyou Field Institute)

Research Interests

Phylogeography of vascular plants and terrestrial non-vascular cryptogams (bryophytes and lichens) with an emphasis on species narrowly restricted to alpine and hyperoceanic environments in Pacific Northwestern North America.  Application of methods in molecular systematics to testing hypotheses about the origins of the alpine and hyperoceanic floras. Comparative study of genetic variation within and among populations of geographically widespread vs. geographically restricted species from those environments.

Historical evolution and origins of rare lineages and the practice of conservation biology as it applies to naturally rare species. Application of knowledge about stenoclimatic floras from geographically restricted mesohabitats to the problem of monitoring the effects of climate change on the biota.

Taxonomic and floristic research for treatments of several genera and families included in the forthcoming Flora of North America, Vol. 29, Marchantiophyta. Future research plans include a series of research expeditions into the North Cascades and coastal archipelagos of British Columbia and southeastern Alaska, and eventually to the Aleutian Islands.

Phylogeographic analysis of molecular and morphological variation in Gaudichaudia (Malpighiaceae), a genus of vines with a mixed mating system forming a hybrid complex among tetraploid lineages. Methods include analysis of restriction sites on the chloroplast genome, randomly amplified DNA, and morphometric analysis. Recent taxonomic revisions include description of six new species.


2002. Six new species and taxonomic revisions in Mexican Gaudichaudia (Malpighiaceae). Madroño 49(4):237-255.

2002. Reticulate ancestry in Mexican Gaudichaudia (Malpighiaceae) analyzed with RAPD's and southern hybridization. Madroño 49(4):256-273.

2002. Bryophyte expedition on the Santa Margarita Ecological Reserve, in the Peninsular Ranges of Southern California. Evansia 19(1): 1-8. [with co-authors K.Kellman, J.Spence, L.Stark, J.Shevock, W.Doyle].

2001. Pacific Northwest sea stack cryptogams:  I. Scapania scandica in Oregon. Evansia 18(3): 73-81. A satellite project publication for the International Biodiversity Observation Year, DIVERSITAS.

2001. Cryptocolea. Bryophyte Flora of North America, Provisional Electronic Edition, Buffalo Museum of Science.  In pressin: Flora North America Vol. 29, Marchantiophyta. Oxford University Press.

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