Achnatherum in South America:
how many species are present?
A potential undergraduate research project (not funded)

Current treatments of South American grasses recognize 3 species of Achnatherum, one in Chile, one in Argentina, and one in Mexico. Preliminary study suggests that the three are not morphologically distinct. Because all three have, supposedly, been found in the United States as weeds, it is important to determine whether this is the case or, if not, how many species can be distinguished and how to do so.


  1. How many morphological distinct entities are there within the Achnatherum caudatum species group?
  2. What is the distribution of the entities in South and North America?

South American specimens of the taxa have been borrowed for this study from two leading US insititutions. They need to be examined in detail with particular attention to the supposed distinguishing features. Multivariate analysis will be used to explore the implications of the data. The results are publishable.

Interested? Contact Dr. Mary Barkworth ( No previous knowledge of grasses or multivariate anlysis is needed but candidates should have a good track record in math and stats courses.

Think Plants