Research and Conservation in Southern Sonora, Mexico
 Opuntia robusta (nopal rodajón, tuna tapona) 
     
    
        
        Opuntia robusta near Maycoba, Sonora. Photo: Mark Dimmitt  | 
        
        Opuntia robusta in the Sierra Oscura above San Bernardo, Sonora. Photo: Mark Dimmitt  | 
    
    
        
        Opuntia robusta flowering in cultivation. The pads of this clone can reach 18 inches wide; it is probably from a population south of Sonora. Photo: Mark Dimmitt  | 
        
        Opuntia robusta in fruit on Mesa del Campanero near Yécora, Sonora. Photo: T.R. Van Devender |