The Desert Edge: Flora of Guaymas-Yaqui Region of Sonora, Mexico. 2 volumes. 2023. illus. (col.). 1178 p. 4to. Hardcover.

The Desert Edge flora features plant life at the southern margin of a desert, bounded by the sea and by the north­ern reach of the dry tropics. The three-way intersection of desert, sea, and tropics creates a richly varied flora. It is a landscape parched during the long dry seasons and quickly greening when it rains. It is a place marked by cycles of civilization.

A central focus of this book is the Sierra El Aguaje - the rough-and-tumble mountains, riparian canyons, bajadas and shores north of San Carlos that were long ago designated for conservation status as the Reserva Cajón del Diablo, a status without legal significance.

The vascular plants of the Guaymas–Yaqui region in­clude 837 native and non-native taxa (species, subspecies, varieties, and hybrids) in 115 families and 474 genera. Non-natives established in the flora area total 78 taxa, 26 of which are grasses. An additional 46 non-natives are not established as reproducing populations. Twenty taxa are endemic to the flora area.

More than 160 plants have been described (named) from specimens collected in the region, although many of these names are now relegated to synonymy. Edward Palmer’s collections, beginning in 1869, are the basis of more than one-third of these taxa (57 out of 162). We provide abbreviated publication information in the species accounts for all type collections from the flora area.