Cactus

A plant that comes in numerous varieties and is almost instantly recognisable by almost anyone in the world, the cactus makes a great addition to any garden provided you are able to give it adequate care. The cactus family boasts and impressive number of species totalling over 1750 currently known with potentially numerous types that have yet to be discovered. The word itself is derived through Latin and originally comes from Ancient Greek there it’s name (kaktos) was used by Theophrastus to denote a spiny plant about which you could not be certain of it’s identity. Cacti are also well known for growing in numerous shapes and sizes with some being small enough to sit neatly by a window and some varieties being taller than the average human.

The majority of all cacti species grow in habitats that are subject to periods of drought which has been popularised in many popular culture cartoons and films. Most cacti also grow in extremely dry environments that are completely unsuitable for almost all other forms of plant life, including being able to grow in the Alacama Desert which is one of the driest places on the planet. Because of their evolution in extremely dry environments the cactus is a plant that has adapted the ability to store large reserves of water and this feature is perhaps one of the most well known features of the cactus plant.

What cacti are truly renowned for however is their signature spines that typically cover the entirety of the plant itself. Whilst the spines are a great defense against herbivores seeking food, they also serve another purpose with the spines helping to prevent water loss by reducing the air flow around the plant and providing a small amount of shade. The spines don’t provide a large amount of shade but in the most extreme of dry environments even a little goes a long way.

The typical cactus shape, so popularised by cartoons, is the single stem with two ‘branches’, almost in the shape of a person holding up both of their arms. Although there are many cactus species that do grow in this shape, there are many varieties that grow in smaller globe shapes instead. This shape is ideal for water storing as it gives the cactus the greatest volume that is possible combined with the lowest possible surface area from which the water can actually escape via transpiration.

Whilst cacti look great in any garden, they are also a source of food in many countries that have warmer, dryer environments and almost any cactus flesh is actually edible to humans. Although it’s important to make sure that you know what kind of cactus you are eating as a number of varieties have psychoactive effects.