An Agreeable Landscape: Historical Botany and Plant Biodiversity of a Sonoran Desert Bottomland, 1855–1920

John Russell Bartlett found that it presented an agreeable landscape: irrigated fields, fine grass, and a winding line of tree canopies down the valley of the Santa Cruz River at Tucson, southern Arizona, in 1852. In 1913, John James Thornber collected aquatic plants from the sides of a cemented ditch at the foot of the very hill from which Bartlett had cast his gaze. By then, the free-flowing waters of the valley had all but disappeared. For now more than a century, scientists have measured, sampled, drilled, gauged, modeled, and photographed the watershed of the Santa Cruz River, aiming to reconstruct the process behind this pattern.

Largely implicit in previous landscape histories—treating changing geomorphology, hydrology, settlement, and socioeconomics—have been those very things that made the landscape green and so memorable in the accounts of nineteenth-century travelers. Spanning nearly seven decades—from the earliest scientific surveys to cross the Sonoran Desert to the arrival of the Southern Pacific Railroad, the organization of the University of Arizona to the founding of the Desert Botanical Laboratory—An Agreeable Landscape: Historical Botany and Plant Biodiversity of a Sonoran Desert Bottomland, 1855–1920 is an accounting of plant life in the Santa Cruz and Rillito valleys of the Tucson Basin. Primary documents, historical narratives, and more than 1,200 dried plant specimens are the foundation for this exploration of floristic richness, bottomland habitats, and ecological change.

Over time, a convergence of cultural, political, and scientific currents at Tucson—arguably the seat of the Santa Cruz watershed—have made this the best-documented riparian ecosystem in the Sonoran Desert for this time period. This original compilation affords a vantage point from which to view the historic bottomland among the spectrum of riparian conservation in the region today, as well as to inform those ongoing efforts in a watershed that, even diminished, remains a biological resource of international importance.