Bitty Roy Barbara (Bitty) Roy

Associate Professor
University of Oregon
Department of Biology

B. S., Evergreen State College, 1982
M. S., Southern Illinois University, 1985
Ph.D., Claremont Graduate School, 1992
Member of: Center for Ecology & Evolutionary Biology

Contact Information:

Office: 461B Onyx Bridge
Telephone: (541) 346-4520

Lab: 474 Onyx Bridge
Telephone: (541) 346-4520



  • Influence of pathogens on host biodiversity
  • Evolution of resistance and tolerance to disease
  • Interactions between biotic and abiotic stresses (including climate change)
  • Pollination ecology


I am interested in understanding how the ecology and evolution of plants is influenced by their associations with fungi and insects. My work is always hypothesis driven, attempts to address key land management issues, and typically involves international collaborations. My current work is in two areas: floral mimicry and plant invasion biology

I. Floral Mimicry

The understanding of the evolution of mimicry in plants is largely based on concepts developed to explain protective mimicry in animals (Roy and Widmer 1999). Floral mimicry differs because instead of keeping potential predators away, flowers are inviting potential pollinators in. The lack of experimental approaches to a diversity of mimicry systems beyond animals leaves gaps in our knowledge, stalling our ability to develop a broadly applicable paradigm of mimicry.

An unusual example of floral mimicry is found in the orchid genus Dracula, a group of about 150 species in Neotropical could forests. These orchids exhibit a peculiar morphology
of the labellum (the modified lower petal) that appears to mimic gilled mushrooms (Fig. 1). We have recently
shown that this is indeed a good mimicry system: the flowers are pollinated by mushroom visiting flies (Fig. 1) (Endara et al. 2010), mushrooms co-occur with the flowers (Dentinger & Roy 2010 and unpub. data) and visitation to the flowers is increased when mushrooms are nearby (Policha & Roy unpublished data). We have also established that the mushroom-like fragrances emitted by the flowers are almost identical to those produced by co-occurring mushrooms, and that different species of the orchids have different “mushroom bouquets” (Policha, Raguso, Dentinger & Roy unpub. data).

We are currently addressing many questions, including: (1) How is the deception achieved?, (2) What are the flies doing in the mushrooms and orchids?, (3) Can specificity of the mushroom flies explain the diversity of Dracula orchids?

We do our fieldwork at Reserva Las Cedros, a field station in the cloud forest of Ecuador:

Dracula collaborators:

  • Bryn Dentinger, Senior Mycologist, Kew Gardens, UK:
  • Tobias Policha, Ph.D. Candidate, University of Oregon:
  • Jesse McAlpine, Masters student, University of Oregon
  • Tommy Jenkinson, Masters student, San Francisco State
  • Lorena Endara, Ph.D. Candidate at the University of Florida:
  • Melinda Barnadas, Museum Artist:
  • Rocío Manobanda, Botanist, Quito, Ecuador, see Fundacíon Jatun Sacha:
  • Adrián Troya, Entomologist, Quito, Ecuador
  • Luis Espinosa, Entomologist, Quito, Ecuador
  • Rob Raguso, Fragrance chemist & behavioral ecologist, Cornell University, Ithaca, NY:
  • Roman Kaiser, Fragrance chemist, Switzerland

II. Invasion biology of grasses and their fungal associates

The invasive plants we have focused on are grasses. Grasses are extraordinarily important, both ecologically and economically. Grasslands cover about 40% of the Earth’s land, and many of our most important economic plants are grasses, including corn, wheat and bamboo. Because grasses are economically important they tend to be moved around the world with people. An issue that is rarely addressed is that when grasses are introduced into new localities, so are their fungal associates (pathogens, endophytes, mycorrhizae). These fungal associates, both positive and negative, have the potential to be shared with crops as well as native wild hosts.

Current work: Testing the Enemy Release, Enemy Spillover and Enemy dilution hypotheses, (2) Applying the ERH in a metapopulation context in the invaded range, (3) What are the Consequences of fire and logging for the dispersal and establishment of forest invaders?

Primary Invasive Grass Collaborators

Current Students:
  • Kai Blaisdell, PhD Candidate, University of Oregon
  • Roo Vandegrift, PhD candidate, University of Oregon
  • Lauren Poulos, Masters student, University of Oregon
My other websites related to my lab and research
Dracula Orchids Research Blog
Home Page Teaching Publications
CV Climate Change West Eugene Wetlands