Herb

A Herb is an item used to make potions through the Herblore skill. Herbs can be received through monster drops, grown in the Farming skill, or bought from other players. When you receive a herb through a monster drop, it will be unidentified and be named simply "Herb." Before you can use a herb in any potions, you must determine what kind of  herb it is by identifying it. Depending on your Herblore level, you may not be able to identify the herb. If you identify the herb, you are granted experience depending on how advanced of an herb it was. Unidentified herbs, are commonly called unids by players.

Jungle Potion Herbs
These herbs can only be identified after you have started the Jungle Potion quest. These herbs are untradeable.

Also, Goutweed is a rare herb that can be exchanged with Sanfew for random herb types at a 1:1 ratio.

Herbs are grown especially well in the Farming patch from the My Arm's Big Adventure quest, as that patch cannot become diseased.