In many shapes, sprawling, with unorganized contours, cactuses may seem a blight on the land. But take a closer look, especially at their flowers - some small, others gorgeously large.
After all, the cactuses must make themselves attractive to pollenizing insects in order to perpetuate their kind.
None of these floral effusions of the cactuses, surely, can match in interest the surprising night blooming of various members of the genus Cereus. Here is a brief, nocturnal episode which has to do with a sprawling specimen in the Southwest called Lemaireocereus thurberi.
Branches of the plant which, like true cactuses, contain the stored fluid by which the cactus weathers long spells of dryness suddenly produce spiky buds. These sprout from aureoles (nipplelike convections along the ridges out of which also grow the prickly needles).
The budding may occur in spring or summer, a few buds at a time along the ground or even tree-hugging stems. It is to be noted that some plants among the Lemaireocereus grow straight up out of a common stem.
When the flower is ready for the action, shortly after sundown, one of nature's more amazing feats occurs. The upper portion of the spiraling bud seems to unwind. Petals become unglued at the top of the bud and flick outward, unfolding slowly a splendid bloom with its inner bouquet of stamens.
In the case of the blooming pictured here, thurberi nurtured its spikelike bud for several days. The flower that burst free after several hours for the watchers was gorgeously white, 3 to 4 inches across.
The stamens were a delicate inner spray tipped, it would seem, with tiny specks of black pepper.
The bloom languishes in the next day's sun. Then it withers away, leaving a tough, rough-skinned green seed bulk as large as an egg. This fruit, which is edible, turns blood red.
In Mexico the fruit of many cactuses, and indeed the flabby disks of the Opuntia, for example, are of sufficient edible worth to have economic value.
Not to be mistaken for the cereus is another even more gorgeous night-bloomer , the leaf or orchid cactus. Its rigid, heavy branchings seem almost identical with those of the cereus, but its needles are smaller and much less troublesome.
The orchid cactus belongs to the genus Epiphyllum, of which there are about 15 species. It differs from most other cactuses in that, while it often clings to a host tree or plant, it sustains itself independently.
The orchid cactus sports an enormous white, red, or yellow tubelike flower. Some of the flowers grow up to 15 inches long. The blooms fold up like a glove when morning arrives.
Cactuses are native to North and South America, although they are now collector's items in many parts of the world. They are well represented in the American Southwest, but Mexico is first in variety and abundance of form. Some cactuses also grow in colder areas, such as Canada and the tip of South America.
Up to 1,500 species are known to exist.