The traveler who has viewed the Southwestern panorama of nature from its
sagebrush to its spruce trees has indeed seen most of it. The spruce
which grows wild only well up on the higher mountains is familiar to
everybody because it has become a favorite in formal planting
everywhere. But the sages—who knows them? To the tenderfoot, almost any
gray plant is “sage.” To my friends the cowmen, sage means commonly
saltbush. To my friends the foresters, sage means an artemisia. But
there are romantics to whom “purple sage” is Apache plume, which is a
member of the wild rose family.
Some popular education would seem to be desirable. And this applies,
too, to the cacti, for there is more misinformation about them than
anything else that grows, runs, or creeps—except rattlesnakes. The
clever people who design travel folders and pictorial maps almost always
put saguaros in New Mexico. But saguaros do not grow in New Mexico. That
is final! And the yucca is not a cactus. That also is final. Nor yet the
ocotillo—that defiant, splendid denizen of the desert which flaunts the
scarlet torch of flowers. The question that is always on the surface as
one writes of plant life in the Southwest is, “Who wants to know?” The
picnicker wants to know the names—and nothing much besides—of the wild
flowers. My friend the cowman already has the names; that is, the common
ones. If I chance to mention blue grama grass, he gently corrects me,
“black grama.” Then if I mention black grama, he says, “no, white
grama.” But at least he is concerned about something more important than
nonscientific names. He wants to know if the plant is something that a
lean old cow can eat, whether it stays green in winter, and if it will
hold the soil in place. The tourist who pilots car and passengers some
six hundred miles between breakfast and bedtime asks only what he was
looking at. The rest of us who go into the mountains often enough to be
impressed by the layer-cake succession of plants on their slopes can,
with the aid of some reading, amass a store of knowledge where others
amass only mileage. On a tour, it is mileage or knowledge. One has to
choose.
Actually, our New Mexico desert is not dominated by sage. That honor is
held by the creosote bush, called by some of the old-timers
_greasewood_, _Covillea glutinosa_, by some of the scientists—along with
five other synonyms. Like the mesquite with which it shares the same
general habitat but _does not intermix_, it occupies an immense spread
of territory, roughly from Texas to California. Since no livestock will
eat it and the ground it occupies is equally useless for agriculture
because of aridity and stoniness, creosote is a veritable coyote for
survival. The traveler descending from Taos to Santa Fe need not look
for it. The sage of that locality, which gives the landscape its
singularly mournful aspect, is a true sage. With good reason the cowboys
call it _black sage_.
In 1846, Lieutenant Emory, as he rode southward with the Army of the
West, first encountered the creosote as he approached Socorro. The
northward extension of the plant is at the same point today, and the
range of mesquite extends only a few miles farther north. These two
remarkable plants are the main markers of the Lower Sonoran Zone. In the
same arid, stony, broken country, the traveler will find an abundance of
cacti, and these plants are usually supposed to be the most tenacious of
all tenacious growing things. Actually, in southwestern Arizona and
neighboring parts of California there are whole areas where the aridity
is too severe for cacti, but for our state—let it stand. Everybody, of
course, has noted the grotesque shape of the plants, but not everybody
has noted that the shape was chosen with a canny intelligence. A globe
exposes less surface (that is, the vulnerable area for evaporation) than
any other solid of equal volume. And a cylinder is second best. Another
thing—cacti being succulents are filled with a watery sap or juice which
quickly coagulates after a wound and stops the waste of moisture.
Furthermore, the plant’s aggressive root system is arranged so as to
capture the grounds scanty moisture most quickly and completely after
rains.
Cacti of more than sixty species occur within our state, but more than
nine tenths of the plants seen along the highway—unless they are brought
together for a garden collection—can be grouped into one genus, the
_Opuntia_. The family likeness is shown not by the shape or general
appearance but by the fact that all are jointed. Both the cane cactus
(also called cholla and elkhorn) and the pancaked prickly pear, unlike
the big barrel cactus and the numerous small species which resemble it
in shape, have joints and may therefore be rightly called opuntias. The
“pancakes,” it may be remarked, are not leaves but divisions of the
stem. A cactus gets along without leaves. So a good rough-and-ready test
is this: if it has leaves, it is not a cactus—which eliminates ocotillo,
yucca, agave, sotol, and so on.
The barrel cactus is sure to be seen growing beside service stations in
the southern part of the state. Its name as well as its size identifies
it. The flowers and the large lemon-shaped fruits are worth a glance. If
they do not occur on the south side of the plant, it has been
transplanted and turned. The evidence is as trustworthy as the presence
of moss on the north side of a tree in the forest.
The barrel cacti, the opuntias, acacias, the ocotillos, along with the
creosote and mesquite already mentioned, have a way of growing along
together in what is called a plant society. These all belong in the
bottom layer of the cake called the Lower Sonoran Zone, which is best
seen on the Rio Grande mesas near El Paso.
The layer next above it comprises the foothill country of the Upper
Sonoran Zone, which includes most of the state of New Mexico. Some of
its common markers are juniper, piñon, oak of various species including
live oak, mountain mahogany, mescal, yucca, beargrass, and the famous
blue grama grass. It is exhibited all along the Continental Divide in
the southwest part of the state but nowhere so well as in the Fort
Bayard Reservation. There a tract, protected for three generations from
woodcutting, fires, and intensive grazing, offers a large-scale picture
of the lovely land that once was New Mexico. There the character and
amount of vegetation astounds the visitor who is familiar with only the
close-picked, parched aspect of the landscape that generally borders the
main highways. When seen from the air, the very color of the
grass-mantled earth is many shades lighter than that of the bare
overgrazed ranges a few miles to the south. And the difference can be
seen by anybody.
The foothills are dotted, not covered, with juniper and piñon. The
dwarfed, rounded little junipers (properly enough called cedars) leave
the traveler unprepared to believe that they will anywhere become
respectable forest trees. Yet in the Burro Mountains, the alligator-bark
species, finest of them all, reaches a diameter of five feet and an age
of about 1000 years. The wood has an extraordinary fragrance, and its
smoke tells the neighbors for blocks around that you are warming
yourself at the fireplace. Another notable thing about the wood is its
resistance to decay in the earth. I have removed pieces of it from
subterranean ruins of the Mimbres culture which, according to the best
archaeological opinion, are some eight hundred years old.
The yuccas deserve a story by themselves. One small, unimpressive
species greets you on the meadows at the foot of Raton Pass; others have
to be searched out along high limestone ridges where the foothills are
deciding to become mountains. The one chosen for our state flower is the
tall yucca (_Yucca elata_), a superb species best seen along the
Continental Divide near Silver City. The genus reaches its greatest size
in the grotesque Joshua tree, which never fails to attract the eye on
the Mohave desert in California.
The century plant has a name that always gets attention. But let us be
sure we mean the same thing. Rightly, it means the mescal, the favorite
food of the Mescalero Apaches. Besides these two names, it is called
also maguey and, no doubt, Spanish dagger along with various other
spine-tipped plants. All of which clinches the argument for a name which
for all users is a certain designation for one object and only one. It
is not just because botanists like to appear learned that they call this
plant _Agave parryi_. That title is as descriptive as middle C for one
key on the piano, and in the same way international.
[Illustration: Yucca plants]
Everyone inquires about the century plant’s life expectancy. An
insurance man might make an inference from the name. The plant is a big
compact cluster or rosette of rigid, upward-pointing, spadelike leaves,
each four or five inches in width and each tipped with a vicious, stout
thorn. Year after year the plant just sits there by a boulder,
unnoticed. I question whether anything alive on the desert has a better
life expectancy. As far as my observations go, it has no diseases. It is
invincible to drouth. Freezing does not harm it, and fire cannot burn
it—although a yucca even when green will flame up like a torch. No
hungry old cow can crop it, and no rodent gnaws it, at least not enough
to do harm. And since the Indians have gone on reservations, no human
uses it. So it stays there.
In fact, nothing less than a caterpillar can leave a dent on it—not, of
course, the caterpillar that eats young tomato plants, but the
Caterpillar that pulls heavy road machinery. The plant just does not die
before maturity, it would seem. A remarkable organism, indeed! But after
many, many years, depending on the amount of moisture it receives, it
makes up its mind to flower. In one tremendous effort, it shoots up a
twelve-foot flower stalk at the rate of several inches a day. The
blossoming is a final, dramatic, beautiful gesture, for by the time the
flowers have withered, the great tenacious plant has turned to a ghastly
purple and is dead.
On the high slopes where the last yuccas end and only a few junipers
remain in the race for survival, the yellow pines come in to mark off
what is called the Transition Zone. The pines need no description, no
printed promotion. The traveler, any traveler, can appreciate them
although he might not be stirred to the slightest interest by the lovely
yuccas. Since the beginning of time, the pines, fragrant, cheerful,
companionable, have been man’s best friend. Among the ponderosa pines
takes place most of the hunting, most of the camping, much of the
picnicking. There is no danger that the tourist will overlook the pine
belt and the pines for they are probably the most numerous tree in New
Mexico.
[Illustration: Piñon needles]
Above them, the classifications are less clearly defined and ecologists
are less inclined to agree on zonation. The Canadian Zone, if we settle
on that name, occurs only in small areas on the map, and most of them
north of Santa Fe. These are high ridges and island peaks that tower
high enough to tempt the Engelmann spruces. Yet some of these islands
occur as far south as the Mogollon Mountains and thus bring Canadian
Zone scenes almost to the Mexican border. For hardy ecologists who want
to explore high ridges and horns of bare stone which rise as clean as a
hound’s tooth clear up into the Arctic-alpine Zone, it is necessary to
enter Colorado.
Engelmann spruce forests may be associated with the 10,000-foot level.
The blue spruce is very similar, perhaps only a subspecies, but it comes
in a little lower. The Engelmann makes a dense forest hardly allowing
invaders, but the blue is more tolerant, less austere. It loves the
water and is the natural companion of chill, cascading trout streams.
Though fond of shadow, it seems to grow equally well where the narrow
canyons widen and admit the sunshine upon the tiny meadows of lush
grass, cranesbill, velvety red cinquefoils, lupines, and yellow
columbines. And when one of these miniature openings is fringed with
spruces whose pointed tips rise sharp against a curtain of azure with
its white cumulus clouds, there you have the loveliest vista in the
mountains.