given landmark to the right or left, to find a dry spring where one
looked for running water--there is no help for any of these things.

Along springs and sunken watercourses one is surprised to find such
water-loving plants as grow widely in moist ground, but the true desert
breeds its own kind, each in its particular habitat. The angle of the
slope, the frontage of a hill, the structure of the soil determines the
plant. South-looking hills are nearly bare, and the lower tree-line
higher here by a thousand feet. Canons running east and west will have
one wall naked and one clothed. Around dry lakes and marshes the herbage
preserves a set and orderly arrangement. Most species have well-defined
areas of growth, the best index the voiceless land can give the traveler
of his whereabouts.

If you have any doubt about it, know that the desert begins with the
creosote. This immortal shrub spreads down into Death Valley and up to
the lower timber-line, odorous and medicinal as you might guess from the
name, wandlike, with shining fretted foliage. Its vivid green is
grateful to the eye in a wilderness of gray and greenish white shrubs.
In the spring it exudes a resinous gum which the Indians of those parts
know how to use with pulverized rock for cementing arrow points to
shafts. Trust Indians not to miss any virtues of the plant world!

Nothing the desert produces expresses it better than the unhappy growth
of the tree yuccas. Tormented, thin forests of it stalk drearily in the
high mesas, particularly in that triangular slip that fans out eastward
from the meeting of the Sierras and coastwise hills where the first
swings across the southern end of the San Joaquin Valley. The yucca
bristles with bayonet-pointed leaves, dull green, growing shaggy with
age, tipped with panicles of fetid, greenish bloom. After death, which
is slow, the ghostly hollow network of its woody skeleton, with hardly
power to rot, makes the moonlight fearful. Before the yucca has come to
flower, while yet its bloom is a creamy cone-shaped bud of the size of a
small cabbage, full of sugary sap, the Indians twist it deftly out of
its fence of daggers and roast it for their own delectation. So it is
that in those parts where man inhabits one sees young plants of _Yucca
arborensis_ infrequently. Other yuccas, cacti, low herbs, a thousand
sorts, one finds journeying east from the coastwise hills. There is
neither poverty of soil nor species to account for