Succulent plants, also known as fat plants, are water-retaining plants adapted to arid climate or soil conditions. Succulent plants store water in their leaves, stems and/or roots. The storage of water often gives succulent plants a more swollen or fleshy appearance than other plants, also known as succulence. The bodies are often amazingly symmetrical and drought brings out strong colours in the stems, a bit like sun tanning. Some plants give stunning results. As if that were not enough, they also produce, bright and stunning flowers – yes, contrary to common belief they flower very freely – with some flowers up to a foot across.

Many succulents come from the dry areas of the tropics and subtropics, such as steppes, semi-desert and desert. High temperatures force plants to collect and store water in order to survive long dry periods. These fascinating plants have evolved all over the world to live in areas of low rainfall. The difficulties they face in arid environments have led to the evolution of an amazing variety of body shapes with fattened stems and leaves to store water against the coming droughts.

Occasionally groups became so specialised at dealing with drought that a whole group of plants became succulent. In the Americas this happened and the Cactus family of plants developed. Cacti, then, are a related group of plants which all display succulence: they store water in their fat stems. There are about 1,500 different types of cacti which all originate in the Americas, especially from Mexico. Many are very spiny, but some have no spines at all.

Other succulents are plants originating from many other groups, which evolved independently around the world to survive in the same dry climates by storing water. A few of these are spiny. There are probably about 8,000 different types of other succulents with South Africa being a hot spot.

Some well-known types of cactus and succulents

• Prickly pears, which are grown commercially for their fruit, and found also all over Malta.

• Christmas and Easter cacti are seen in many homes flowering beautifully in the dark part of the year.

• The Carrion flower, another succulent whose flower smells of rotten meat and so attracts insects to pollinate it.

• The Mother-in-law’s Armchair, a particularly spiny cactus.

• Living stones, South African succulents, which hide from predators by disguising themselves as stones.

• Some American Indians use the Peyote as a drug in their religious ceremonies.

• Their difficult life means that many have evolved peculiar chemicals, to fend off insects and to help in the drought. Some of these have proved useful to man, like the Aloe vera which is a succulent used for many medicinal purposes.

• The century plant, which flowers irregularly, provides sisal, roofing materials, sewing needles, beer and tequila for Mexicans.