Nether Wart

Nether Wart is a plant grown in The Nether. It can be found within Nether fortresses on Soul Sand. Nether Wart in inventory can be placed onto Soul Sand by right-clicking (as if it were a seed), where it will grow.

Growth & Growing Conditions
Nether Wart will only grow in the Nether and can only be planted on Soul Sand. When left alone, each plant will grow through three distinct stages in a similar fashion to wheat. Each plant has a 0.00407% chance of growing to the next stage every 1/20th of a second, meaning that they can potentially grow very quickly or take as long as several hours to fully develop, so large farms are recommended to maximize one's chances. Factors such as light level or proximity to lava do not appear to affect the growth rate of Nether Wart, and it does not respond to bone meal.

As of 1.0.0, Nether Wart can only be grown in the nether, which tends not to be loaded as often for most players, resulting in less chances for Nether Wart to grow. One way to alleviate this is to do potion brewing in the Nether so that the Nether Wart will keep growing and there will hopefully be enough Nether Wart grown for when you need more Awkward Potions. However, potion brewing in the Nether presents logistical costs and large investments in iron due to the necessity of cauldrons and making bucket runs to keep them filled.

A possible work around for the water issue is fill your water bottles in the overworld and store them in a chest in the nether until needed.

As of Beta 1.9 Prerelease 4, mining Ice with a pickaxe with the Silk Touch enchantment causes Ice to drop, which can then be brought to the Nether for water. This was fixed in Minecraft 1.0, and now Ice is unobtainable.

Harvesting
There are three visual stages of development. During the first two stages, it will yield one Nether Wart. On the final, largest stage, breaking Nether Wart will produce 2-4.

Trivia

 * Nether Wart will not break when stepped on, unlike Wheat crops, nor will Ghast fireballs destroy them (though, fire caused by the fireballs will).
 * It makes the same sound as stone when destroyed.
 * In the code, Nether Wart is called "netherStalk" for the block and "netherStalkSeeds" for the item.
 * Nether Wart only grows in The Nether. Attempting to grow it anywhere else will cause it to plant, but not actually grow.