1. The Plant of the West The Cactus

2. Cactus The Cactus plant is believed to be native to the Americas. There have been calculated to be between 1,500 to 1,800 species of cacti. Cacti come in all shapes and sizes from round and short through to thin and tall. The smallest grow just about an inch high and about 0.4 inches across. The tallest cactus can reach heights close to 66 or more feet and up to 5 feet in diameter.

3. Many different shapes and sizes

4. Some Facts In place of leaves, cacti have special organs called areoles. These are like buds and they are arranged regularly along the ribs of the stem or on the tips of tubercles. They produce spines which help to protect the stems from being eaten by predators.

5. Areoles

6. The Cactus Some cacti have swollen stems which contain water-storage tissues, and the stems have a thick waterproof epidermis, usually covered with a waxy cuticle to help prevent water loss. Plants of this type are termed stem succulents. The cacti typically have extensive root systems, spreading just below the soil surface, so that they can absorb even the relatively small amounts of water that moisten the soil surface during light showers of rain.

7. Facts The water is quickly collected by the roots and stored in thick, expandable stems for the long summer drought. The fleshy stems of the barrel cactus are pleated like an accordion and shrink as moisture is used up. These pleats also channel water to the base of the plant during rain showers.

8. Facts To conserve water, cacti and other succulent plants open their pores (or stomata) to absorb carbon dioxide only during the night when it is cool. Because of the nature of the cactus to conserve water they grow very slowly. In the barrel cactus, growth may be as little as 1/4 inch per year and most young sprouts never reach maturity.

9. The Cardon Cactus It is the tallest Cactus in the World, mainly found in parts of Mexico Some have measured up to 70 feet high and weigh up to 25 tons. Cardon Cacti have also been calculated to live up to 300 years. Like other cacti that are tall and narrow, they depend upon bats for pollination.

10. The Cardon Cactus

11. Bats & Pollination

12. The Cardon Cactus Because it has no leaves, photosynthesis takes place on its skin. Modified epidermal cells in the skin of the stems, called ''chlorenchyma'' do the work of converting sunlight to energy.

13. Prickley Pear Flower

14. Prickly Pear Cactus Life Span They are known to live well over 20 years. Size There are several different varieties of prickly pear cactus each growing to different sizes. The most common species in the Sonoran Desert is the Engelmann prickly pear which grows up to 5 feet tall and can grow to a width of 10-15 feet.

15. Prickly Pear Cactus Both fruits and pads of the prickly pear cactus are rich in slowly absorbed soluble fibers that may help keep blood sugar stable. Has been of many uses: Mosquito Repellent Dye Paint Sunburn Treat diabetes Jelly

16. Prickly Pear Flower

18. Prickly Pear Fruit