9. Joshua-tree

Another of the narrow-leaf yuccas and largest of the genus, the joshua-tree is restricted in its range to the Mojave-Colorado Desert, of which it is the principal indicator. Blossoms, which do not open as wide as those of other species, grow in tight clusters at the tips of the branches, appearing in March and April. Joshuas do not blossom every year, the interval between flowerings depending upon rainfall and temperature. A small night lizard is dependent upon the joshua-tree, at least 25 {species of birds find nesting sites in it, and numerous insects, spiders, and scorpions live in its dried leaves and fallen branches.}

JOSHUA-TREE