American Cacti

With only a few exceptions, the true cacti are found exclusively in the western hemisphere, from Canada to the southern tip of South America, the West Indies, and the Galápagos Islands. Cacti are often referred to as xerophytes, plants adapted to extremely dry conditions and capable of withstanding drying for extended periods. The most obvious characteristic of cacti are the spines, which serve a number of purposes besides protection, such as casting shadows on the cactus to protect it from the sun, reducing leaf surface area, which reduces water loss, and serving as points of condensation for moisture, which then drips down for use by the roots.

Christmas Cactus
The Christmas cacti are a group of bushy perennial cacti growing to a height of about 16 cm (5 in). These cacti are often found in shaded areas in rich, well-drained soils.








Organ Pipe Cactus
The organ pipe cactus grows in parts of Arizona, Baja California, and northern Mexico at elevations below 1000 m (3000 ft). The organ pipe reaches a height of 6.6 m (20 ft) and has white flowers and red fruit.




Saguaro Cactus
The saguaro cactus, common in Arizona’s desert areas, branches only after it has reached a height of about 5 m (about 15 ft). The saguaro grows very slowly, approximately 2.5 cm (approximately 1 in) per year, and can reach heights of up to about 15 m (about 50 ft). Featured on a United States postage stamp in 1962, the plant’s waxy white blossom is Arizona’s state flower.








Barrel Cactus
There are four species of barrel cactus in the genus Ferocactus growing in parts of Baja California, Mexico, Arizona, and California at elevations below 2000 m (6000 ft). Depending on the species, barrel cactus plants reach a maximum size of 1.6 to 3.3 m (5 to 10 ft). The flowers are generally a yellow, greenish-yellow, purplish-red, or orange color.






Prickly Pear Cactus
The prickly pear cactus is found throughout the southwestern United States, Baja California, and the Sonoran Desert region of Mexico. Prickly pears have whitish, yellow, orange, or red flowers and greenish-brown, yellow, yellowish-green, red, or purple fruit, which are suitable for human consumption. The cactus plants themselves are also edible and are commonly used for livestock feed.





Jumping Cholla Cactus
The jumping cholla, native to rocky deserts and hillsides of Baja California, northern Mexico, Arizona, and New Mexico, grows to a height of 5 m (15 ft). The plant has lavender flowers and a greenish fruit that grows in a chainlike fashion over a period of years.

Cactus

Cactus, common name for the family comprising a peculiar group of spiny, fleshy plants native to America. The family contains about 1650 species, most of which are adapted to arid climates. The fruits of cacti are important sources of food and drink in many areas to which they are native. Because cacti require little care and exhibit bizarre forms, they are popular for home cultivation and are coming under increasing pressure as a result. More than 17 kinds of cacti now face extinction because of plundering by avid collectors and professional poachers, especially in the southwestern United States and northern Mexico.

Cactus plants usually consist of spiny stems and roots. Leaves are greatly reduced or entirely absent. Only in two genera are fully formed leaves present. The stems of cacti are usually swollen and fleshy, adapted to water storage, and many are shaped in ways that cause rain to flow directly to the root system for absorption. The roots form extensive systems near the soil surface, assuring that a given plant will absorb the maximum amount of water from a wide area; plants in deserts are usually widely spaced.

The most distinctive vegetative feature of cacti is the areoles, specialized areas on the stems on which stiff, sharp spines usually grow. Some cacti lack spines but have hairs or sharp, barbed structures called glocids on the areoles. Areoles develop from lateral buds on the stems and appear to represent highly specialized branches.

The flowers of cacti are often large and showy and occur singly rather than in clusters of several flowers. The perianth (floral tube) does not consist of sharply differentiated sepals and petals, but rather of a series of bracts (modified leaves), which gradually grade into sepals and finally into showy petals. The flowers have many stamens; the ovary is inferior and fused to the perianth. The fruits are often brightly colored and fleshy.

Scientific classification: Cacti make up the family Cactaceae. Cacti with fully formed leaves are classified in the genera Pereskia and Pereskiopsis. The night-blooming flowers and the saguaro plant are classified in the genus Cereus. The Christmas cactus is classified as Schlumbergera bridgesii.

See Pictures of Cactus

Grape

Grape, common name of an edible fruit in the buckthorn family, and of the vines that produce the fruit. The European grape has been used as food since prehistoric times. Grape seeds have been found in remains of lake dwellings of the Bronze Age in Switzerland and Italy and in tombs of ancient Egypt. Botanists believe that the Caspian Sea region was the original home of the European grape. Distribution of seeds by birds, wind, and water carried the plant westward to the Asian shores of the Mediterranean. Grape culture, practiced in Palestine during biblical times, was introduced in the Mediterranean region by seagoing Phoenicians. The ancient Greeks cultivated grapes, and use of the fruit was later adopted by Rome and its tributary territories.

Grapevines are stems that climb on walls and fences by means of specialized supporting organs, called tendrils. Palmately veined leaves arise alternately along the stem. In most varieties, tendrils arise opposite two of every three successive leaves. Flowers, usually greenish, are borne in clusters and have staminate and pistillate flowers sometimes occurring on separate plants. Fruit is borne on 2-year-old canes, which are removed after harvesting the grapes.

Scientific classification: Grapes belong to the family Vitaceae. The European grape is classified as Vitis vinifera, the northern fox grape as Vitis labrusca, the summer grape as Vitis aestivalis, the riverbank grape as Vitis riparia, and the muscadine grape as Vitis rotundifolia.

Hawthorn

Hawthorn, common name for any of a genus of small trees of the rose family. Hawthorns are native to temperate regions and are widely cultivated in the form of hedges. They have dense, sharply thorned branches; single, irregularly toothed leaves that turn to brilliant colors in autumn; tiny, red fruits even throughout the winter; and fragrant, white flowers borne in clusters. The best-known species is the English hawthorn, also called the mayflower. Species native to the United States include the Washington hawthorn, found in the southern states, and the cockspur hawthorn, an eastern species with shiny leaves and long thorns. The genus includes about 20 species in Eurasia and more than 100 in North America. Many of the latter are believed to be hybrids.

Scientific classification: Hawthorns belong to the family Rosaceae. The English hawthorn is classified as Crataegus laevigata, the Washington hawthorn as Crataegus phaenopyrum, and the cockspur hawthorn as Crataegus crus-galli.

Rose

Rose, common name for a medium-size family of flowering plants with many important fruit and ornamental species, and for its representative genus. Worldwide in distribution, the rose family contains about 107 genera and 3100 species.

The rose family is placed in an order with 24 other families. This order is sometimes referred to as the rose order. Other important members of the order include the saxifrage family and the stonecrop family. Another family, the coco-plum family, occurs in the lowland Tropics and contains about 400 species, several of which are used locally for their timber, oilseeds, and fruits. Perhaps the best-known member of the family is the coco plum, found in southern Florida on sandy beaches and swamps; its sweet fruits are made into jelly or preserves.

About 70 genera of the rose family are cultivated for food, ornament, flowers, timber, or other uses. Although worldwide in distribution, the family is most abundant in north temperate regions and contains many of the most important fruit trees grown in temperate areas. These include apple, pear, peach, plum, cherry, apricot, almond, nectarine, prune, loquat, and quince. The rambling, usually thorny raspberry, blackberry, and dewberry, or loganberry, are members of a genus of the rose family that also includes the common bramble. The strawberry is also a member of the family. In addition the family contains many important ornamentals: chokeberry, cinquefoil, hawthorn, shadbush, cotoneaster, firethorn, flowering cherry, flowering quince, and mountain ash.

Roses may be grown in any good, well-drained soil. Although different varieties respond better to certain soil and climate than to others, sandy soils are usually not as favorable as clay soils, warm temperatures are always preferred, and the plants grow best when not set among other plants. Cow manure is the preferred fertilizer, but other organic fertilizers, especially composts, are also used. The plants usually require severe pruning, which must be adapted to the intended use of the flowers. Most rose varieties are grown by budding on an understock (lower portion of a plant) propagated from seeds or cuttings. Roses must be sprayed frequently with insect poisons and fungicides.

Scientific classification: Roses make up the family Rosaceae of the order Rosales. The representative genus is Rosa. Hybrid perpetuals, or remontant roses, are derived mainly from the hybrid species Rosa borboniana; polyantha roses from the hybrid species Rosa rehderana; tea roses from Rosa odorata; and China roses from Rosa odorata and Rosa chinensis.