In this booklet we are dealing with DESERT flowers, so it seems logical
to take a moment to check upon the desert itself. What is a desert, and
how may we recognize one when we see it?
“A desert,” stated the late Dr. Forrest Shreve, “is a region of
deficient and uncertain rainfall.” Where moisture is deficient and
uncertain, only such plants survive as are able to endure long periods
of extreme drought. Desert vegetation is, therefore, made up of plants
which, through various specialized body structures, can survive
conditions of severe drought. In general, the deserts of the world are
fairly close to the equator, so they occur in climates that are hot as
well as dry. Plants in the deserts of the Southwest must endure long
periods of heat as well as drought.
In North America, major desert areas are located in the general vicinity
of the international boundary between Mexico and the United States. Due
to various differences in elevation, climatic conditions, and other
factors, certain portions of this Great American Desert favor the growth
of plants of certain types. Based on these general vegetative types,
botanists have catalogued the Great American Desert into four divisions,
as follows (see map):
1. Chihuahuan Desert: Western Texas, southern New Mexico, and the
Mexican states of Chihuahua and Coahuila.
2. Sonoran Desert (Arizona Desert): Baja (Lower) California, northern
Sonora, and southern Arizona.
3. Mohave-Colorado Desert (California Desert): Portions of southern
California, southern Nevada, and northwestern Arizona.
4. Great Basin Desert: The Great Basin area of Nevada, Utah, and
northeastern Arizona.
It is of especial interest to note that certain plants such as
Creosotebush (_Larrea tridentata_) seems to thrive in several of these
desert areas while others are found in great abundance in only one.
Plants that grow in profusion in only one desert are spoken of as
“indicators” of that particular desert. Any person interested in desert
vegetation soon learns the major indicators, not only of the different
deserts, but of different sections or elevations in the same desert.
Here are some of the better-known indicator plants:
1. Chihuahuan Desert: Lechuguilla (_Agave lechuguilla_);
2. Sonoran Desert: Saguaro (_Carnegiea gigantea_);
3. Mohave-Colorado Desert: Joshua-tree (_Yucca brevifolia_);
4. Great Basin Desert: Sagebrush (_Artemisia tridentata_).
This publication deals with the common plants and flowers of the
Chihuahuan, Sonoran, and Mohave-Colorado Deserts. Since these names are
strange to many visitors to the Southwest, the writer has taken the
liberty of applying descriptive names as synonyms. In this booklet the
Chihuahuan Desert is called the Texas Desert, the Sonoran Desert is
referred to as the Arizona Desert, and the Colorado-Mohave Desert is
considered as the California Desert.
Whenever possible, the desert in which a particular species of plant is
most common is indicated; however, this should not be interpreted too
rigidly as most of the plants in this book grow in more than one desert
and some grow in all.
Because the Great Basin Desert is a region of higher elevation and is
influenced by other factors which are not common to the three portions
of the Great American Desert covered in this booklet, its vegetation is
more like that of the plateaulands and foothills of the Southwest.
Therefore, the flowers of the Great Basin Desert are included in a
companion booklet, Polly Patraw’s “Flowers of the Southwest Mesas.”
NATIONAL PARKS AND MONUMENTS
AS WILDFLOWER SANCTUARIES
Someone has called National Parks and Monuments “The Crown Jewels of
America.” A part of their beauty and irreplaceable value is because the
approximately 180 units of the National Park System which extends from
Florida to Alaska and from Hawaii to Maine, are and have been wildflower
sanctuaries. Not only do native plants live under natural conditions,
but they are protected from picking, from grazing of domestic livestock,
and from the competition of exotic species, and from other activities of
mankind that would disrupt their normal habitat or disturb their native
way of life.
Men in the uniform of the National Park Service feel complimented
whenever visitors show an interest in the natural features of the areas
they protect, and are happy to assist them in locating rare species or
especially beautiful or spectacular specimens. Range and grazing
specialists are more and more using the natural vegetation of National
Parks and Monuments as “check plots” to aid them in studying ways and
means of preserving the level of grazing value on the open ranges.
Within the desert areas of the Southwest there are a number of National
Parks and Monuments. Three Monuments (Joshua Tree in California, Organ
Pipe Cactus and Saguaro in Arizona) have been created primarily to save
from exploitation and destruction outstanding areas of typical desert
vegetation. Although the others have been established to protect and
preserve geologic, historic, or archeologic values of national
significance, they are all wildflower sanctuaries. In California, Death
Valley National Monument is outstanding in its variety of desert
flowers. Lake Mead National Recreation Area, of which Hoover Dam is the
center, has exceptional displays of various forms of desert plants. A
great variety of desert vegetation will be shown and, if desired,
explained to the interested visitor, by National Park Service rangers at
Chiricahua, Tonto, Montezuma Castle, Casa Grande, and Tumacacori
National Monuments in Arizona. Of course the really great displays of
desert botany and ecology are featured at Organ Pipe Cactus and Saguaro
National Monuments.
In New Mexico, Chihuahuan Desert vegetation is particularly abundant at
Carlsbad Caverns National Park. A number of desert forms, especially
interesting because of the effect upon them of the ever-moving gypsum
dunes, are found at White Sands National Monument, near Alamogordo.
Another outstanding Chihuahuan Desert wildflower sanctuary is Big Bend
National Park in southwestern Texas.
Photography is encouraged in all of the National Parks and Monuments. By
asking a ranger, you will be able to learn where the various flower
displays may be found, the best time of day to obtain good results, and
other suggestions helpful in obtaining photographs of desert wildflowers
at their very best.
Each year the following magazine and radio program present bulletins on
moisture and other pertinent conditions in the desert, spotlight areas
in which outstanding wildflower displays are developing, and advance
suggestions relative to areas in which spectacular displays may be
expected.
Desert Magazine, Randall Henderson, Editor, Palm Desert, California.
Richfield Reporter, western radio stations.