Ranarr weed is a herb that can be cleaned at level 25 Herblore. It is the fifth lowest level herb available, yet is one of the most valuable herbs in the game, as it widely used in the Herblore skill to make prayer potions when combined with snape grass. It can also be combined with white berries to make defence potions, though this is a major loss of money, since ranarr weeds are so valuable.
Due to its value, this herb is often grown by players (with a Farming level of 32) by planting ranarr seeds in the various herb patches in RuneScape. Ranarr seeds are often in high demand, and as a result, planting ranarr for profit is a gamble. However, it is also an uncommon drop from various monsters. One notable monster for dropping this herb is Flesh Crawlers, as they are easy to kill and drop this herb frequently.