Though the saguaro may be the park's centerpiece, after wet winters the spring wildflower display can be breathtaking. The brilliant gold of the Mexican poppy is often the first-noticed bloom, while penstemons, lupines, desert marigolds, brittlebushes, and globe mallows cont… Though the saguaro may be the park's centerpiece, after wet winters the spring wildflower display can be breathtaking. The brilliant gold of the Mexican poppy is often the first-noticed bloom, while penstemons, lupines, desert marigolds, brittlebushes, and globe mallows contribute their lively colors of red, lilac, blue,.