ARIZ Associated Researchers Richard Felger, Sue Rutman, Jim Malusa and colleagues are comprehensively documenting "the modern and fossil vascular plant flora of the contiguous protected areas of Organ Pipe Cactus National Monument, Cabeza Prieta National Wildlife Refuge, and the Tinajas Altas Region in southwestern Arizona—the heart of the Sonoran Desert."
(Felger et al., 2013, Phytoneuron 2013-5, p 1).

Each volume was published in Phytoneuron and is available for download here:

Part one pdf Introduction

Part two pdf Checklist

Part three pdf Ferns, lycopods, and gymnosperms

Part four pdf Magnoliids

Part five pdf Monocots except grasses

Part six pdf Poaceae – grass family

Part seven pdf Cactaceae – cactus family

Part eight pdf Acanthaceae – Apocynaceae

Part nine pdf Convolvulaceae – morning glory family

Part ten pdf Berberidaceae, Bignoniaceae, and Boraginaceae

Part eleven pdf Brassicaceae and Burseraceae

Part twelve pdf Campanulaceae to Cucurbitaceae

Part thirteeen pdf Euphorbiaceae – spurge family

Part fourteen pdf Fabaceae – legume family

Part fifteen pdf Fagaceae - Lythraceae

Part sixteen pdf Malpighiaceae - Moraceae

Part seventeen pdf Nyctaginaceae - Plumbaginaceae

Part eighteen pdf Polemoniaceae - Phlox

Part nineteen pdf Polygalaceae - Simmondsiaceae

Part twenty pdf Solanaceae - Zygophyllaceae

Part twenty one pdf Asteraceae – Aster Family