Cactus Flowers

We've been home for about a week, but my mind continually reflects on the beautiful plants, flowers, and landscapes of Arizona in the spring.

On my last day in Arizona, Ron drove me to the airport, but not before stopping to see some of the neighborhood flowers. Linda had scouted them out during her morning jog and suggested that we pause to appreciate them. These plants were well worth the detour, especially the magnificent white cactus flower shown above. Does anyone know their names? It seems a shame that I remain so ignorant of something I admire so deeply.