New publication
by Michelle (Shelley) McMahon
The Legumes of Arizona – an Illustrated Flora and Reference [1] was published in summer 2024 by the Botanical Research Institute of Texas Press. The book was many years in the making! Dozens of authors and illustrators contributed original works, making it a really special endeavor and pretty unique among floras.
Dalea formosa
S. McMahon
The project was initiated by Dr. Mark Bierner, Director of the Boyce Thompson Arboretum (which, at the time, was co-managed by UA, BTA, and State Parks). As BTA Director, leading the Desert Legume Program (DELEP) was also part of his position. When he arrived, he noticed that the last comprehensive treatment of legumes in Arizona was decades old [2]. In addition to the deep legume expertise in Matt Johnson at DELEP, Mark noticed there were other legume people around (Dr. Marty Wojciechowski at ASU and myself here at UA). So, although Mark’s specialty is the aster family, he launched a legume book project!
The aim of the book is to present information on all 89 genera and 381 species that are native, naturalized, or commonly cultivated in Arizona. To set the context, eight introductory chapters provide perspective on geology, geography, weather, and climate, as well as a history of botanical exploration and a description of modern bioprospecting. Keys cover the non-cultivated and commonly cultivated taxa together, to facilitate identification of any legume in the state. Maps provide generalized ranges, each genus has at least one hand-drawn illustration, and several pages of color photos are included. Cultural and horticultural uses are provided throughout, largely contributed by Matt Johnson.
Arizona is rich in biodiversity, with over four thousand plant species, and the legumes are no exception – indeed, they form about 7% of our state’s flora. Our many biomes are inhabited by temperate groups like Astragalus and more subtropical groups like Dalea, not to mention all the arid-land genera such as Prosopis and Parkinsonia, non-native members of Acacia, and its native segregates Vachellia and Senegalia.
Therefore, this was a big project, involving legume researchers from around the world who kindly contributed their expertise and time to write treatments. Original artworks, very generously provided by an amazing community of botanical illustrators led by Margaret Pope, visually communicate details of selected species. Managing Editor Kirsten Lake worked closely with these authors and illustrators for years, and Mary Welch-Keesey provided eagle-eyed scientific review and copy editing, throughout the lifetime of the project.
Plant systematics is an ever-evolving field, with new discoveries and newly realized relationships affecting species' circumscriptions and generic assignments. Floristics is also always on the move, as species’ ranges expand and contract, new remote canyons are botanized, or newly invasive taxa become established. We (the editors) hope that this reference will serve as a starting point for understanding legume diversity within our state, and we (the UA Herbarium) look forward to tracking changes as they happen. I will be working with our fabulous students to build legume-specific resources on our website over the coming year. Questions, comments, and especially new discoveries are very welcome!
- McMahon MM, MB Johnson, KN Lake, MF Wojciechowski, and MW Bierner (eds.). 2024. Legumes of Arizona: An illustrated flora and reference. Sida, Bot. Misc. 64. Botanical Research Institute of Texas, Fort Worth, Texas, USA.
- Kearney, TH and RH Peebles. 1960. Arizona Flora. University of California Press, Berkeley, California, U.S.A.