GROWTH AND HABITAT
This chapter treats of the Opuntia genus of Cactaceæ, the well known group of Prickly Pears whose flower colorings are remembered as being so exquisite and delicate, so vivid and attractive both near and afar, the lovely tints and hues so well graduated from the bases of the petals to their tips and so symmetrical of distribution, that attention is at once focused upon them. There are about two hundred sixty species of the Opuntia, of which eighty-eight are in the United States, eighty-seven in Mexico, and the remainder in South America and the outlying islands. The genus Opuntia includes not only the beautiful Prickly Pear but also the familiar Cholla, that tall, stately, antlered plant of the desert domain which frowns at you from along the highway as you approach our no man’s land from almost any direction. Starting on a fourth trek into the habitats of cactus plants early in May, we shall look for only the colorful Prickly Pears, characterized by their large pear-shaped joints, the “flapjacks” of the desert; characterized also by their large flaming orange and yellow, or occasionally rich purple and red blossoms, which open for only a short time during the day and close when the shadows of the sun begin to bathe the hills in orange and purples as the desert sunset approaches. In a few cases they unfold for a short time the following day, but most bloom for but the one period of five to seven hours or so. Commonly the blossoms change from yellow when they open to orange in the afternoon, and in some species to red-orange. It is also noted that when the flowers unfold for a second day, their bright colorings deepen and darken in orange or red. We find that the clan of the Prickly Pear nearly always have thorns different from those of most other groups of Cactaceæ in that they are only of one kind, though the sizes may vary. In the genus of Opuntia there are no radial nor central spines; the thorns are merely spines in the full sense of the word. We note that the Prickly Pear is really a shrub with many stems branching from the base, and that their pear-shaped joints are in reality stems or branches and are not just leaves as many suppose; the true leaves being very small and scalelike and disappearing after a short time, withering away and falling off. The species grow readily from these pearlike joints, and this is a common method of propagating Opuntia. They will also grow from seeds, but these develop very slowly and require a long time in the ground before they germinate.
Papago Fruit Cactus (Opuntia Blakeana)
Southern Arizona
It is from Tucson, in the rocky foothills of southeastern Arizona, that we start on our long trip across the state and into old Mexico and California. The first of the lovely auroral coloring to attract our notice is the low spreading Prickly Pear called Opuntia Blakeana in honor of Dr. William Blake, who was formerly Geologist and Director of the College of Mines and Engineering of the University of Arizona. Forming in loosely branched clumps on the desert, eight feet or more across and only a foot or so high, this growth is most strikingly characterized by its translucent brown fringe of spicules along the margins of the areolas and its needlelike purplish brown thorns suffused with gray toward the bases. The brilliant orange-red and yellow blossoms, nearly three inches long and as broad, like most of their sister species open and close in the daytime, the sepals greenish yellow toning off to an orange-red base. Blooming time is in April and May, the fruit comes on in July; the latter when ripe is used for food by the Pima and Papago Indians of Arizona, and while they eat it both raw and cooked it is not utilized as is that of some of the other and larger varieties.
PAPAGO FRUIT CACTUS (Opuntia Blakeana)
Delicate Prickly Pear (Opuntia delicata)
Southern Arizona
At altitudes of three to five thousand feet in the sandy and clay loams across southern Arizona one may see a prickly pear called delicata on account of its small size and its slender joints and spines. This baby Opuntia was only recently discovered and is considered a rare find, though little is known about its distribution. The tiny plants are sometimes but three inches high, growing to ten inches in different specimens, with one or several stems, long needlelike spines and large yellow flowers, as usual blooming in the morning and closing up their petals in the afternoon. New and interesting specimens of the cactus clan are discovered now and then, and it gives the botanist and the layman much pleasure to study and classify them, to look up their haunts and habits and place them where they belong, so that all may see and know them.