How to Identify Cactus Trees

Cacti are easily identifiable plants, although you are not likely to come across them anywhere other than a desert. Follow these steps to recognize their distinctive characteristics.

Instructions

1. Note that cacti are a type of plant called a "succulent." They have slightly woody outsides and fleshy insides. Many of them have ribbed sides that provide shade for the cactus. They go dormant in the winter, sloughing off fine roots and keeping the pores closed at night. They grow quite slowly (approximately 1 inch per year) and live from 50 to 200 years.

2. Study the root system of a cactus. This will give a clue as to how it collects enough water to sustain it. The root system is shallow (4 inches deep), widespread and relatively short. Living in the desert, the roots must be able to collect as much water as possible in a short amount of time, so it sends up feeder roots that lay approximately 1/2 an inch under the soil.

3. Look at the stem of the plant. Although the cactus comes in a wide variety of shapes and sizes, there are some aspects they have in common. Cacti have a waxy skin that makes them nearly water-proof and the leaves (spines) funnel water to the base. They also have pores that open at night to exchange gases, then close during the day to hold in moisture.

4. Notice the differences between cacti and other species of trees. In place of foliage the cactus has spines that vary in shape and texture. Some are straight, others are hooked. They can be long, short, sharp or soft. Cacti have a peculiarity called an 'areole' which is composed of two opposing buds; from the upper grows either the flower or a side shoot, and from the bottom grow spines.

5. Examine the beautiful flowers that bloom on the cactus once a year. They grow in bright colors and last only days. Seeds are propagated by wind, birds or animals. Certain cacti have fragile, loose stems that break off easily and form new plants wherever they fall.