closeup of foliage
National Parks in Palm Springs Area picture - Its not exactly a tree in the usual sense: its actually the yucca brevifolia , a giant member of the lily family,. It grows quickly at higher elevations (i.e. the Mojave Desert), has a top-heavy branch system, and can live for hundreds of years. The leaves are evergreen, spear-like, and grow to as much as a foot (30+ cm) in length. When there has been enough rain plus a cold snap in the winter, they may bear cream-coloured flowers and even fruit. Otherwise they just wait patiently for the right conditions. For complete information about this unusual specimen, go to: http://en.wikipedia.org/wiki/Yucca_brevifolia .