Apache Plume (Fallugia paradoxa) usually begins blooming in April here in southern Arizona and can continue blooming sporadically until the fall. A good place to observe these native shrubs here in Tucson is above 4000 feet along the Catalina Highway in the Santa Catalina Mountains.
The white flowers on this member of the rose family are quite attractive and look like wild roses, but the most spectacular feature of this shrub is its mass of feathery seeds.
Because of its attractive flowers and seeds, Apache Plume is commonly grown in xeriscape (low water use) gardens. It does require a bit more water than other Tucson desert shrubs, which is why it's usually found growing wild in the slightly cooler and rainier upper foothills.