D. Dougall - NPS
There are also many blooming perennial plants that live here, and although they may not be quite as showy, they can be depended on to bloom in all but the driest of years. These are the plants that provide the staples for desert dwelling insects, birds and animals, many of whom rely on pollen, nectar or fruits to survive the dry summer months. These hardy plants, such as the agave, rabbitbrush, yucca, many species of cacti, and others, including shrubs and trees, tend to bloom each year, even when conditions are too dry for the annual wildliflowers. They also bloom for longer periods of time, and often into the hottest summer months and late fall, providing a colorful show for visitors from early spring until October or November.