The Annals of the Missouri Botanical Garden, published quarterly since 1914, contains peer-reviewed papers primarily devoted to systematic botany and evolution. The Annals reflect the global mission of the Garden, with contributing authors from the Americas, Africa, Europe, Asia, and Australasia.

CONTENTS OF THE ANNALS OF THE MISSOURI BOTANICAL GARDEN, VOL. 91, NUMBER 1

A Revision of Trisetum, Peyritschia, and Sphenopholis (Poaceae: Pooideae: Aveninae) in Mexico and Central America. Victor L. Finot, Paul M. Peterson, Robert J. Soreng, and Fernando O. Zuloaga

Revision of Metastelma (Apocynaceae--Asclepiadoideae) in Southwestern North America and Central America. Sigrid Liede and Ulrich Meve

A Taxonomic Revision of the Paeonia anomala Complex (Paeoniaceae). Hong De-Yuan and Pan Kai-Yu

Phylogeny of Smelowskia and Related Genera (Brassicaceae) Based on Nuclear ITS DNA and Chloroplast trnL Intron DNA Sequences. Suzanne I. Warwick, Ihsan A. Al-Shehbaz, lz Connie A. Sauder, David F. Murray, and Klaus Mummenhoff

Phylogenetic Relationships of Vulpia and Related Genera (Poeae, Poaceae) Based on Analysis of ITS and L-F Sequences. Pedro Torrecilla, Jose-Angel Lopez-Rodríguez, and Pilar Catalan

Geographical Diversification of Tribes Epilobieae, Gongylocarpeae, and Onagreae (Onagraceae) in North America, Based on Parsimony Analysis of Endemicity and Track Compatibility Analysis. Liliana Katinas, Jorge V. Crisci, Warren L. Wagner, and Peter C. Hoch

Floral Biology of Hesperantha (Iridaceae: Crocoideae): How Minor Shifts in Floral Presentation Change the Pollination System. Peter Goldblatt, Ingrid Nänni, Peter Bernhardt, and John C. Manning

Lineage Sorting and Phylogeography in Lithocarpus formosanus and L. dodonaeifolius (Fagaceae) from Taiwan. Tzen-Yuh Chiang, Kuo-Hsing Hung, Tsai-Wen Hsu, and Wen-Luan Wu