Saguaro cactus, an enduring symbol

Like most of my friends, it begins to bloom at 40

When I first came to Tucson, Ariz., on a visit a dozen years ago, I got my first glimpse of the saguaro cactus and nearly swooned.  For my entire life I had gotten no closer to viewing these Western giants than when, as a child growing up in the Northeast, I watched cartoons featuring Wile E. Coyote.   

The more I learned about this marvelous plant and a…