NAD Pathways Grade 2 selection for Theme 3: Living Things. The intriguing life cycle of the saguaro cactus and the complex web of life that characterizes the North American Sonoran desert is effectively explored in this involving picture book. The author's text captures the reader with its steady pace and often delightful echoes of cumulative nursery tales. She weaves an amazingly large range of facts into this simple story of a fragile ecosystem, and helps children comprehend just how much plants and animals depend upon one another for their survival.