Arizona Cacti

Cacti are superbly adapted to the desert environment but can also be found in the tropics, high mountains, along the coasts and in the jungle. They are leafless and the stems are coated with wax to retard evaporation. As excellent storehouses of water, they expand and swell during periods of moisture and shrink when it becomes arid. All cactus are succulents but all succulents are not cactus.

Their most noted feature is the spines and thorns, which are, really modified leaves. Spines can be flat, hooked, curved, round, hair like or feathery. A long taproot serves as the anchor to hold the plant and long horizontal roots run along under the soil surface to absorb any wetness that becomes available. Saguaros for instance can have surface roots that go out as far as they are tall.

Flowers are sometimes very showy, with large colorful blooms as in the saguaro and prickly pear. They come in a variety of colors and some are night blooming. The fruit is as varied as the plant and most are edible. Many have been used traditionally to make juice, jellies and candies. Several animal and bird species depend on them for food. In fact it is possible that if the cactus didn’t flower many species of animals and especially insects would go extinct.

Some cactus is very tall such as the Cordon or Saguaro and others are only a couple of inches tall. Both tall species and very small ones may live for over one hundred years. Some grow quickly such as the prickly pear and cholla, but most are medium to slow growing. Saguaros may be 35 years old and only 5 or 6 feet high and it is not unlikely that they get their first arm at 50 to 70 years of age.

A few of the better-known cacti are described here, using their popular names.

Giant Saguaro
(Carnegiea Gigantea)

This cactus can reach heights of more than forty feet and may grow numerous arms or branches. It is covered with spines and blooms at the tips of its branches with a large three-inch white blossom. The fruit is red and is harvested by the Tohono O’odham Indians in June and July. The Saguaro can store enormous amounts of water for times of drought by swelling with liquid and shrinking when dry. Sometimes more than a ton of liquid is sucked up after a Monsoon rain. Many birds make their nests in the holes created by woodpeckers in the trunk and branches.
In Mexico there is a very similar cactus that is called the Cordon and they are often confused. Saguaros originated in the Tropical deciduous forest in the vicinity of Alamos, Mexico and were not originally a desert-adapted plant. However, over the many thousands of years they became able to move north and Colonize the Sonoran Desert. Over many tens of thousands of years they have come and gone in Arizona depending on the temperatures and amount of water available. Currently it is believed they have been here since the end of the last ice age episode maybe 8 to 11 thousand years ago.
They are a tall cactus because where they originated they had to be able to grow just taller than the trees so that they could get their flowers pollinated by the insects, bats, and birds.

Branched Pencil Cholla
(Cylindropuntia Ramosissima)

This type of cholla grows from three feet to eight feet tall with numerous branches that cross over each other. Thorns can be two inches long and grow vertical to the stem. The stems are hard and covered by plates, making it unique among the cholla. These stems produce flowers and fruit. Blossoms are yellow with red tinges. The one inch long, oval fruit looks like a burr, being covered with dry, brown spines. This cactus can propagate by falling to the ground and rooting. Most cholla cactus has developed a unique method of colonizing new areas. Because they have wicked barbs on the thorn tips it is not uncommon for them to hitch a ride on an animal such as a deer that may brush up against it and then carry it many miles away before it is dislodged.

Fish Hook Barrel Cactus
(Ferocactus Wislizenii)

The barrel is a short, fat, cylindrical plant that can reach twelve to twenty inches in diameter and may grow two to six feet tall. It has long, hooked spines that resemble fishhooks and can be from one to two inches in length. Large yellow or red flowers appear in July and August. The fruit is oblong, yellow and ripens in February. This is a common cactus in the Sonoran desert and while beautiful it can cause serious damaged if walked into. More than one tourist has tripped and broken something because of these succulents.

Christmas Cactus
(Cylindropuntia Leptocaulis)

This woody plant is compact and bushy, growing about three feet tall. Stems are about six inches long, dull green in color and will separate from the plant if touched. The spines are one to two inches long and flowers are yellow. The fruit is bright red and is visible from November to February. There are legends that say ancient Americans used this cactus as a gift to celebrate their equivalent of Christmas.

Organ Pipe Cactus
(Lemaireocereus thurberi)

The Organ Pipe Cactus National Monument is one home of this cactus. It grows ten to twenty feet tall and clusters of large branches can be fifteen to thirty feet in diameter. The branches are five to eight inches in diameter and reach heights of ten to twenty feet. They are covered in two-inch long spines. Flowers appear only at night with white centers and red outer petals. The Native Americans use the round, red fruit as a source of sugar. This is a slow to medium growing cactus that is highly prized by landscapers. It is completely protected in the wild in the U.S. and in areas of Mexico where it is more common.

Teddy Bear Cholla
(Cylindropuntia Bigelovii)

This plant prefers hot, dry rocky hillsides and reaches two to five feet in height. It has a central trunk and arms covered with one-inch spines. Small white flowers and one-inch long fruit are characteristic. Stems detach easily when touched. In color this succulent is a golden yellow and when the sun is behind it either early or late it makes for a very striking photograph. Be especially careful near this plant and even watch where you are walking near these beautiful but painful plants.

Stag Horn Cholla
(Cylindropuntia Versicolor)

This member of the cholla family grows from sit to twelve feet tall. The trunk and stems are woody and are covered with 1/2-inch long spines. Flowers appear in various colors and the fruit is large with many seeds. This is a fairly common cactus in the Sonoran desert and most people classify them as weeds. They have very pretty flowers that come in many shades from whitish pink to yellow or even bright red. They are very easy to trim and transplant and many people are starting to use this misunderstood cactus more in landscaping.

Pancake Pincushion
(Mammillaria Heyderi)

The pincushion cactus is flat, about three inches in diameter and is covered with spines. It has small, white flowers about one inch long and its fruit is red, about 1/2 inch long and is edible. As with most Mammillaria cactus it is not uncommon to not see this fine specimen until after the Monsoon rains which often bring out the beautiful flowers, which typically form a crown near the top of this quiet beauty. There are many species of relatives to this pincushion and they are somewhat difficult to tell apart except for the flowers, which are fairly distinctive to each species.

Beaver Tail Prickly Pear
(Opuntia Basilaris)

Named from the shape of its pads, the beaver tail thrives in sandy soil, growing in clumps with broad smooth stems. It is covered with small, wooly stickers rather than spines. Pads are from two to five inches wide and five to eight inches long. It blooms in April with two inch, large pink, purple, white or yellow flowers. The fruit is long and narrow, about 1 1/4 inches long and one inch in diameter. Be especially careful with this succulent as the small little spines are a disaster if you so much as brush lightly up to one. They have microscopic barbs on each of the dozens that will lodge in your cloths or skin with the slightest touch. They are very difficult to get out as rubbing or scraping only causes them to dig in deeper and they are very irritating if not almost painful for several days. This all a ploy to keep you or any potential enemy from touching or in any way bothering this otherwise innocuous cactus.

Purple Prickly Pear
(Opuntia Gosseliniana)

This plant grows two to five feet tall and has round, flat pads growing from a central stem. The flowers are large, yellow and appear in April. The fruit is purple, one inch and oblong. It may have spines on its trunk and tiny, brown wooly stickers cover the pads. Most often this succulent is called Santa Rita variety, but in actuality it is just a relative.

Arizona Rainbow Hedgehog
(Echinocereus Ridigissimus)

This species of hedgehog cactus is cylindrical, has one stem or trunk about fourteen inches tall and is covered with spines. The flowers are small and may be red or purple, usually appearing on the top. The fruit resembles tiny red chili peppers. This not a common cactus and you will be very lucky if you actually see one.

Hen & Chickens
(Coryphantha Aggregata)

This plant begins as one globe shaped specimen about two inches in diameter with small erect spines. It forms small clusters and will flower in two-inch diameter, pink or purple blooms. Fruit is green, oblong and reaches about one inch in size. The clusters will spread and it makes a good rock garden or container plant. Found usually in higher, cooler, and wetter areas than the Sonoran desert