The Annals is an international journal primarily devoted to systematic botany and evolutionary biology. We encourage submissions of original papers dealing with significant advances in the taxonomy, phylogeny, conservation, and evolution of plants using morphological and/or molecular characters.

CONTENTS OF THE ANNALS OF THE MISSOURI BOTANICAL GARDEN, VOL. 106

A Contribution to the Characterization of Ruppia drepanensis (Ruppiaceae), a Key Species of Threatened Mediterranean Wetlands
Olga De Castro, Anna Geraci, Anna Maria Mannino, Nicolina Mormile, Annalisa Santangelo, and Angelo Troia

Toward an Updated Taxonomy of the South American Chenopodiaceae I: Subfamilies Betoideae, Camphorosmoideae, and Salsoloideae
Nicolás F. Brignone and Silvia S. Denham

Genome Size in South American Gentianella (Gentianaceae, Swertiinae), with a Special Emphasis on Species from the Bolivian and Ecuadorian Andes
Simon Pfanzelt, Jan Ptáček, Petr Sklenář, K. Bernhard von Hagen, and Dirk C. Albach

The Genus Drypetes (Putranjivaceae) in Liberia: An Annotated Checklist with a New Species, D. liberica
Alejandro Quintanar, David J. Harris, and Patricia Barberá

A Brief Early History of Plant Science in St. Louis and the Partnership between Washington University and the Missouri Botanical Garden
Ralph S. Quatrano and Audrey S. Metcalf

Taxonomic Studies of Diospyros (Ebenaceae) from the Malagasy Region. VII. Revision of Diospyros sect. Forbesia in Madagascar and the Comoro Islands
Alexander G. Linan, Porter P. Lowry II, and George E. Schatz

The Neotropical Croton sect. Geiseleria (Euphorbiaceae): Classification Update, Phylogenetic Framework, and Seven New Species from South America
Ricarda Riina, Benjamin W. Van Ee, Maria Beatriz Rossi Caruzo, Daniela Santos Carneiro-Torres, Rafaela Freitas dos Santos, and Paul E. Berry

Insights into the Taxonomy of Citharexylum (Verbenaceae): A Revision of the South American Taxa
Nataly O’Leary, Laura A. Frost, Fabiana Mirra, and Pablo Moroni

Chromosome Numbers and Ploidy Levels of Some Paniceae and Paspaleae Species (Poaceae, Panicoideae)
Ana Isabel Honfi, Osvaldo Morrone, and Fernando Omar Zuloaga

Taxonomic Revision of the Genus Podagrostis (Poaceae, Pooideae, Poeae)
Ana María Molina, Zulma E. Rúgolo, María de los Ángeles Ferrero, Patricia C. Palacio, Carolina Guerreiro, and Andrea S. Vega

Comparative Floral Micromorphology in Mimosa sect. Calothamnos (Fabaceae)
Mariana C. Grohar, Sonia Rosenfeldt, Renée H. Fortunato, and Matías Morales

Toward an Updated Taxonomy of the South American Maranthaceae II: Subfamily Salicornioideae, Tribes Salicornieae and Suaedeae
Nicolás F. Brignone, Adriel I. Jocou, and Silvia S. Denham

The Phylogenetic Position of Crenea in the Lythraceae Based on Molecular Evidence, and the Transfer of Its Two Species to Ammannia
Shirley A. Graham, Peter W. Inglis, and Taciana B. Cavalcanti

Synopsis of the Genus Pentacalia (Compositae, Senecioneae) in Bolivia
Joel Calvo

A Continuum of Conspicuousness, Floral Signals, and Pollination Systems in Rhynchospora (Cyperaceae): Evidence of Ambophily and Entomophily in a Mostly Anemophilous Family
Ana Carolina Galindo da Costa, William Wayt Thomas, Artur Campos D. Maia, Daniela Maria do Amaral Ferraz Navarro, Paulo Milet-Pinheiro, and Isabel Cristina Machado

Taxonomic Revision of Euphrasia (Orobanchaceae) in South America
Ana Verónica Ortiz, Pablo Moroni, Fabiana Mirra, Rosa María Villanueva Espinoza, and Nataly O’Leary

Assessing the Risk of Extinction of Vascular Plants Endemic to the Yucatán Peninsula Biotic Province by Means of Distributional Data
Germán Carnevali Fernández-Concha, Ivón Ramírez-Morillo, José Eduardo Pérez-Sarabia, José Luis Tapia-Muñoz, Héctor Estrada Medina, William Cetzal-Ix, Silvia Hernández-Aguilar, Lilia Lorena Can Itza, Nestor Eduardo Raigoza Flores, Rodrigo Duno de Stefano, and Gustavo A. Romero-González

Synopsis of Ozobryum (Pottiaceae, Bryophyta), and Sequential Bayes Evaluation of Genus Integrity
Richard H. Zander

Walter H. Lewis: A Life Spent Pushing back the Frontiers of Botany (1930–2020)
Charlotte M. Taylor and Roy E. Gereau

• Editors-in-Chief: Peter Hoch and Aaron Floden