The flowering plants that inhabit the American deserts all have special features that have allowed their species to survive in inhospitable conditions. Many of these features can help the uninitiated to identify the plant, especially when it is bloom. The shape of the flowers, the colors of the blossoms, where they emerge on the plant and other facets of the tree, wildflower, shrub or cactus are useful in identifying the plant.
The shape of a plant, especially a cactus, or the shape of its flower can be a huge clue to help identify it. The popcorn flower is a prime example of this, with a small cluster of tiny white flowers on the end of its stem that resembles popcorn. Barrel cactus is rotund and looks for the entire world like a barrel covered in spines. The flowers of this type of desert plant always flower at the very top of the cactus in a circular pattern. Organ pipe cactus deserves its name, as it looks like a series of interconnected pipes of various heights.
Sometimes it is the seeds of a flowering desert plant, and not the flowers, which are the key to identifying the species. The cottonwood tree, which grows near a water source in parts of the desert, has seeds that attach to fine white hairy tufts, the "cotton" of the tree's name, which blow away in the wind. The mesquite tree develops pods that hold the seeds of the tree from its flowers. The honey mesquite's pods are 8 inches long and a greenish yellow, while those of screwbean mesquite are just 2 inches long but wound in a tight spiral.
When an observer carefully studies the actual flower on a desert plant then she has a chance to match it to the correct species in a field guide. Identifying plants in this manner requires excellent powers of observation. The blue phacelia, for instance, has flowers shaped like bells with five petals joined at the base. The flower is blue and approximately a quarter inch wide, covered with extremely fine hairs. Looking for such features and finding them can make identification possible.
Knowing the elevation of a particular portion of a desert ecosystem plays a role in identifying the flowering plants within it. Certain types will grow only at or below certain elevations--the desert globemallow grows in sandy washes and on the stone strewn hillsides below a 4,000-feet elevation. This is where having reliable topographical maps comes in very handy as they can indicate the elevations of a region, helping someone zero in on what may grow there.
Other distinctive features of flowering desert plants make them recognizable. One is the way the branching trunk of the elephant tree looks like a tangle of elephant legs. Another is how the spines of the fishhook cactus look a lot like actual fishhooks, curved and sharp. The wildflower called "desert pincushion" is similar to what someone used to sewing would stick needles and pins in. These unique aspects of certain desert flowering plants make them easy to identify.