pine, nut-pine, juniper, hop-hornbeam, ash,
maple, holly-leaved berberis, cowania, spiraea, dwarf oak, and other small
shrubs and trees. In dry gulches and on taluses and sun-beaten crags are
sparsely scattered yuccas, cactuses, agave, etc. Where springs gush from
the rocks there are willow thickets, grassy flats, and bright flowery
gardens, and in the hottest recesses the delicate abronia, mesquit, woody
compositae, and arborescent cactuses.

The most striking and characteristic part of this widely varied vegetation
are the cactaceae--strange, leafless, old-fashioned plants with beautiful
flowers and fruit, in every way able and admirable. While grimly defending
themselves with innumerable barbed spears, they offer both food and drink
to man and beast. Their juicy globes and disks and fluted cylindrical
columns are almost the only desert wells that never go dry, and they
always seem to rejoice the more and grow plumper and juicier the hotter
the sunshine and sand. Some are spherical, like rolled-up porcupines,
crouching in rock hollows beneath a mist of gray lances, unmoved by the
wildest winds. Others, standing as erect as bushes and trees or tall
branchless pillars crowned with magnificent flowers, their prickly armor
sparkling, look boldly abroad over the glaring desert, making the strangest
forests ever seen or dreamed of. _Cereus giganteus_, the grim chief of the
desert tribe, is often thirty or forty feet high in southern Arizona.
Several species of tree yuccas in the same deserts, laden in early spring
with superb while lilies, form forests hardly less wonderful, though
here they grow singly or in small lonely groves. The low, almost stemless
_Yucca baccata_, with beautiful lily-flowers and sweet banana-like fruit,
prized by the Indians, is common along the canon rim, growing on lean,
rocky soil beneath mountain-mahogany, nut-pines, and junipers, beside
dense flowery mats of _Spiraea caespitosa_ and the beautiful pinnate-leaved
_Spiraea millefolium_. The nut-pine, _Pinus edulis_, scattered along the
upper slopes and roofs of the canon buildings, is the principal tree of
the strange Dwarf Cocanini Forest. It is a picturesque stub of a pine about
twenty-five feet high, usually-with dead, lichened limbs thrust through
its rounded head, and grows on crags and fissured rock tables, braving
heat and frost, snow and drought, and continues patiently, faithfully
fruitful for centuries. Indians and insects and almost every