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Tuesday
Nov142017

Plant Profile -  Cacti

The Cactus is well known for having unique qualities which helps it to survive in extreme heat and the desert, but that’s not the only reason this plant is fascinating! From special roots and stems, to being a source of food, it’s one nifty succulent – read on to find about more about the wonderful cactus!

Flickr | Matt HoffmanThere is thought to be between 1500 and 1800 species of cacti, with some living to the ripe age of 300 years old! Being a member of the plant family Cactaceae, a family comprising about 127 genera, Cacti are natives to the Americas, ranging from Patagonia in South America through to areas of western Canada. There is one species, however, that is an exception; Rhipsalis baccifera (also known as a “mistletoe cactus”) is also found in Africa, Madagascar and Sri Lanka. There are two suggestions as to how it got from one side of the Atlantic to the other, the first being that back when Gondwana was the supercontinent, the cactus chose both Africa and America as its home when it split into two separate continents, meaning the cactus chose both sides as a home; this is called vicariance. Another suggestion is that of dispersal; it is thought that droppings from migratory birds could have dispersed the Rhipsalis seed in these other locations, as the birds love to eat the fruit of Rhipsalis, delicious little white berries.

Flickr | Dick Culbert

How do they survive the conditions they live in?

Many cacti live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on earth; however, cacti have adapted in order to live in these conditions in numerous ways, aimed specifically at conserving as much water as possible. Almost all cacti are succulents, meaning that they are drought resistant plants which have thickened fleshy parts to store water. The leafless, spiny stem is the characteristic feature of the majority of cacti, and the surface of the stem may be smooth, or covered in protuberances of various kinds, varying from small bumps to larger ones. From these little bumps comes one of the cactus’ most notable feature – its spines. A cactus’ spines are technically just highly modified versions of plant leaves, and they have two roles. Firstly, they keep the cactus safe from birds and animals who sometimes decide to eat the plant, usually only for its water, and secondly, they prevent loss of water through transpiration.

pixabay | anon.The stem is ribbed, or fluted in shape – the shape depends on how much water the cactus is storing. The shape of the stem allows a low surface area-to-volume ratio which reduces water loss. In addition, many cacti have roots which spread out wide, but don’t go particularly deep into the soil. When rain falls after a drought, cacti are able to form new roots very quickly. Some cacti have been reported to take water to hydrate themselves for as long as 12 hours, from as little as 7mm of rainfall. There is no other plant species that is as well equipped for weather conditions like the cacti…

Flowers, Fruit and Food

It seems almost strange to think of this spikey plant as having beautiful flowers, but they do! Cacti are flowering plants, meaning that every kind of cactus is actually capable of blooming when it is mature. Whether or not the cactus blooms or not depends on a variety of things, such as its age and the care it receives – some cacti won’t bloom until they’re past 30 years old, whilst others will never bloom at all.

As well as providing flowers, some cacti even grow fruit, and provide food. For anyone who’s ever watched The Jungle Book and wondered what a prickly pear is, it is in fact an oval, reddish-purple fruit that grows on the prickly pear cactus! Pitaya, more commonly known as dragon fruit, is now eaten all over the world, and can be found in Asia even though the plant itself is indigenous to Latin and Central America.

Flickr | Chris GoldbergThe cactus plant features in many tales about the West, being portrayed as the water-bearing plant that saved thirsting cowpokes who had become lost in the desert. The most amazing feature of this plant is that this plant serves as a natural water reservoir. Cactus liquid is not clear like water, and looks like a thick viscous substance, but nevertheless, this liquid is absolutely safe for human consumption. In addition, the cactus has even become a delicacy in some parts of the world, with nopales, the pad like leaves of the nopales, being eaten in various ways – just make sure you remove the spikes…

Conservation

Unfortunately, protecting wildlife does not only refer to animals. Cacti are under as much of a threat as other as other species, with the three main threats being grazing, development and over-collection. Numerous human development projects in Mexico have destroyed large areas inhabited by cacti, particularly dam building, urban development and the conversion of land to agriculture. In addition, cacti are still over-collected for sale in many parts of the world, and illegal collecting of the succulent in the wild continues to pose a threat.

pixabay | veroucchedduFrontier not only runs conservation projects that aid the home of the cacti, such as our Peru Amazon Rainforest Conservation project, but also runs global projects with the aim of aiding and preserving our planets special ecosystems and communities. Check them out here to find out how to get involved.

By Fran Collis - Online Journalism Intern

Frontier runs conservationdevelopmentteaching and adventure travel projects in over 50 countries worldwide - so join us and explore the world!

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