Research Training Program

Emma Harrower
University of British Columbia
Vancouver, Canada

Paul Peterson, Ph.D.
Supervising Scientist
Department of Botany

"It was amazing to be in a scientific research community that still engages in the exploration of the cultural, biological and geological diversity on Earth. This summer opened my eyes to all the different avenues of natural history, an experience I would have received nowhere else."

The Defining Characteristics of Two Related Grasses

The grass family (Poaceae or Gramineae) is the fourth largest flowering plant family and contains about 11,000 species in 800 genera. Grasses are found on every single continent of the world and are the most important plant family for food production. Despite their significance, many range grasses have been much overlooked by research scientists. Mountain muhly (Muhlenbergia montana (Nutt.) Hitchc.) is an important range grass found in the southwestern United States, northern Mexico and Guatemala. Slimstem muhly (Muhlenbergia filiculmis Vasey) is a relative to M. montana but has a restricted distribution, being found only in the southern Rocky Mountains. M. filiculmis grows at higher elevations than M. montana and is shorter, has smaller leaves, smaller florets and shorter awns. However, specimens with intermediate morphologies are known. Despite the confusion, there have been no detailed numerical studies to test the hypothesis that there are indeed two species rather than a single, highly variable species. Testing the hypothesis, this project involved taking physical measurements of 19 characters and then running the data through multivariate analyses. If individuals cluster into two different groups, then it will confirm that there are two different species. The results can also tell which characters are the best at distinguishing between the species. In addition, DNA was extracted from populations of M. montana and M. filiculmis for an AFLP study to clarify genetic relationships. If populations of M. filiculmis are not readily distinct and fall within the range of variation in M. montana, then the current taxonomic treatment of recognizing these two species will need to be changed. Confirming the identity of M. montana and M. filiculmis provides valuable information to our understanding of biodiversity on Earth and is especially important in light of global warming as habitats become degraded.

This research was supported by an endowment from the Smithsonian Women's Committee.

Letter of gratitude Letter to The Honorable Max Berry