Cactus

Cacti
Ferocactus pilosus (Mexican Lime Cactus) growing south of Saltillo, Coahuila, northeast Mexico
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Caryophyllales Family: Cactaceae Juss.

A cactus is a kind of plant. The plural of cactus can be cacti or cactuses or cactus. In science all genera of cacti (as the whole) are named Cactaceae.

Cacti first came from North America or South America. Many people like to grow cactus in pots or gardens. Now cacti have spread to many other parts of the world.They are part of a very important food chain.

Many cacti live in dry places, such as deserts. Most cacti have and sharp thorns (stickers) and thick skin. There are many shapes and sizes of cacti. Some are short and round; others are tall and thin. Many cactus flowers are big and beautiful. Some cactus flowers bloom at night and are pollinated by moths and bats. Some cactus fruits are brightly coloured and good to eat. Goats, birds, ants, mice, bats and people eat cactus fruits.

The flower of a Moonlight cactus.

Adaptations

An adaptation is anything that helps a living thing survive and make more of its own kind. Cactuses have many adaptations for living in places that are sometimes dry for a long time. At other times these places can get lots of rain.

Cacti can have many small, thin roots near the top of the soil. These roots take in water quickly after a rain. The same cactus may have one long, thick root called a taproot. The taproot grows deep in the soil. It can reach water when the soil on top is dry.

Cacti store water in thick stems. The stems are covered with tough skin, and the skin is covered with wax. The thick waxy skin slows down loss of water. The leaves of cacti are sharp spines (thorns, stickers). Many animals want the water inside the cactus, but the sharp spines and thick skin protect the cactus.

Many species of cactus have long, sharp spines.

Uses

Cacti are commonly grown as houseplants. They are pretty and easy to grow. Some cacti are grown in gardens, especially in dry areas. Cactus can be used as a living fence. The wood of dead cactus is sometimes used for building.

People eat the fruit of some kinds of cactus, such as dragonfruit and prickly pear. Ciouvhiul insects also eat prickly pears. These insects produce a red coloring used in food and lipstick.

Like many cactus fruits, the dragonfruit has many tiny seeds

Cactus in History

The ancient Aztecs of South America held cactus to be very important. Cactus can be found in many of their sculptures and drawings. The national coat of arms of Mexico shows an eagle, a snake, and cactus.

Christopher Columbus brought the first cactus to Europe. Scientists and gardeners became very interested in cactus.

Prickly pears were taken to Australia in the 19th century for use as a natural fence and for use in the cochineal industry. The cactus spread out of control. Now it has made 40,000 km² of land useless for farming.

From the start of the 20th century interest in cactus has grown. Every year, scientists discover new kinds of cactus. A bad effect of this bigger interest has been the digging up of many cacti from the wild, making some kinds endangered.

Barrel cactus are often grown in gardens.

Cactus stems

A cactus does not have leaves because it lives in dry places. Leaves transpire, and this can waste water. So, the cactus saves water by having no leaves. The green parts of the cactus are actually its stems. Because the stems are green, they do the photosynthesis for the cactus. They also grow prickly needles to protect the cactus from animals that want to eat it.

Genera

Family contains more than 100 genera. Some of them:

• Carnegiea
• Cereus
• Echinocactus
• Echinocereus
• Espostoa
• Gymnocalycium
• Hatiora
• Lobivia
• Mammillaria
• Melocactus
• Myrtillocactus
• Notocactus
• Opuntia
• Pereskia
• Rebutia
• Rhipsalis
• Schlumbergera
• Weberbauercereus

Websites

Simple English Wiktionary has the word meaning for:

cactus

Look up Cactaceae in Wikispecies, a directory of species

Wikimedia Commons has images, video, and/or sound related to:

Cactus

• Cactus and Succulent Society of America
• Cacti & Succulent Picture Gallery
• Cacti Picture Gallery
• Cacti Picture Gallery of Saint-Petersburg Cactus Club
• CactiGuide - many photos, and discussion forum
• A Guide to the Miraculous Cactus World
• Intermountain Cactus: Winter Hardy Cactus
• International site for Succulents with photos, tips and plant database (in 4 languages)
• Cactus of the Death Valley Area
• SucculentCity - Plant Profiles, Photographs & Cultivation Data
• Suculentas.es - Spanish language website with many photographs
• Chilean Cacti, by Chileflora
• Cactus and Succulent Field Number Database
• Lithuanian catus photo gallery
• agoracactus.com.ar Spanish forum
• WWF priority species profile for cacti