Oasis at the Desert Edge: Flora of Cañón del Nacapule, Sonora, Mexico

Cañón del Nacapule cuts into the southeastern flank of the Sierra El Aguaje, a rugged volcanic range about 20 kilometers northwest of Guaymas. Nacapule is included in the Sonoran segment of the Gulf Coast subdivision of the Sonoran Desert. The bi-seasonal (summer and winter) rainfall is highly variable. Many plants of tropical origin reach their northern limits in this region or do not extend farther north in the arid coastal desert of western Sonora.