Cactus

Cactus is a block that is only available in Alpha mode. The block has one texture put on all sides of the block, one put on the top, and a third on the bottom of a cactus cross-cut. It can be mined easily without any tool. When the player touches a cactus, half a heart of damage is taken, and when an item touches a cactus the item disappears.

It appears on Sand in vertical stacks that can be one to three blocks tall, 1x1 across. Cacti can rarely be found on a beach, but are abundant in desert biomes.

Due to a biome bug(Only confirmed in Multiplayer so far), as of Patch 1.2.1_01 in the desert biome a cactus can spawn floating in midair one to two blocks off the ground. However, the game will still think the there is a cactus block under it, so the block directly under the floating cactus block is impassable, and can only be destroyed by destroying the visible sand block under it.

Cacti can only be placed on sand or other cactus blocks with no horizontally or vertically adjacent blocks, unless they are placed in water, in which case they can be placed directly next to one other block. Cacti are able to grow without light. When the spot a cactus is placed in becomes unsuitable (e.g. a block is placed next to them), it collapses into a cactus block that can be collected and re-placed. Each mined block of cactus drops one cactus block.

Cactus blocks are non-flammable.



History
Cactus was first seen in the Seecret Friday Update 5.

Before Seecret Friday Update 6,
 * cactus could be placed anywhere, and did not have the requirement that the space around it be empty. This allowed cactus to be placed to form a damaging floor: both players and mobs take half a heart of damage when they walk on a cactus block. This made it useful for traps, such as a hallway with a cactus block floor, which would quickly kill any mobs that walk on it.
 * mining cactus hurt the player.
 * the texture was different.

Farming
Cactus blocks are quickly farmable. A single cactus block placed on sand will grow to a three-block plant after a set amount of time. Like Reeds, removing the bottom part causes all parts above it to be removed as well, allowing for quick harvesting; one can also "shave" off the upper sections and leave the bottom section planted, but this is not efficient when mining cacti, because any dropped cactus blocks that touch the bottom section will be destroyed, just like any other thrown or dropped block that touches a cactus block. Swords can be used to speed up harvesting, but each cactus will consume two of the sword's uses.

It is possible to construct automated cactus farms. If there is space available above a 1 or 2 block high cactus, but there is a block next to where the new cactus block will be, then the cactus will grow and immediately break off, dropping a cactus resource around its base. Water flows can then be used to move the drops from many planted cacti to a single collection point.

Kaktus