Stephen D. Koch

On the basis of examinations ov over 2,000 herbarium specimens, chromosome counts, uniform culture experiments, field observations, and a statistical analysis of variation, the complex was found to consist of only seven taxa. These fall into three groups according to their chromosome numbers and panicle, spikelet, and caryopsis morphology. A key to the taxa is provided, along with synonymies, descriptions, distribution maps, discussions, and plates illustraing important features for each taxon. No new taxa are recognized, but one new combination is proposed.