Cacti grow in the Kharidian Desert. There are three types of cacti in RuneScape, believed to be based upon North American species:

• Barrel shaped: Ferocactus pilosus (Mexican lime cactus)
• Farming cactus: The saguaro cactus, native to south-western United States
• Prickly pear: Opuntia, one of the most common type of cacti found in North America. In the Kharidian Desert, some prickly Pear cacti may act as a water source; they are designated "Kharidian cactus (Healthy)". Water is added to an empty or partially empty waterskin or vessel in the player's inventory, when a knife is used on a healthy cactus. There is a chance of failure, however, so a player may have to cut more than 1 cactus to bring a waterskin from "Waterskin (1)" to "Waterskin (2)". Success or failure is indicated by a message, as well as the presence or absence of a gurgling water sound. Cutting a cactus successfully grants 10 Woodcutting experience, whilst failing to cut one grants 1 experience. There is currently no way to increase the chance of success.

In real life, the alkaloids in a cactus can make you vomit, which means you'd end up losing a lot of water, and could fall into full dehydration very quickly. It is not recommended for survival in real deserts.

Farming a cactus

A cactus can also be grown with the Farming skill using a cactus seed at the cactus patch in Al Kharid with 55 farming. The seed does not need to be used in a plant pot, but can be planted directly into the patch. The patch does not need watering, and, as of 21 August 2012, can be watched over for six cadava berries. To grow another, use a spade on the patch to clear it first.

Once the cactus is fully grown (560 minutes) it will live forever and will not need to be taken care of. It will regrow up to three cactus spines every 25 mins, which you can harvest with your bare hands. After the completion of the hard Desert Tasks, the cactus patch will always be looked after, and will produce double the number of cactus spines.

Cactus spines are used at 73 Herblore] to make extra strong weapon poison. A farmer will also look after a yew tree for a payment of 10 cactus spines.

Trivia

• When you cut a cactus for water it appears that you are using a bronze throwing knife, instead of a regular knife. This is because, at the time the animation was made, there was no animation for the regular knife. There are now animations for Fletching with a regular knife, but the animation of cutting a cactus has yet to be updated.