Excuse my limited knowledge of the game. Here it goes:
Lets you plant a tree! Create a barrage of trees to annoy the enemy.
The sack can be repurchasable for more tree hp. Can be repurchased 3 items for 3 tree levels.
1 - Small tree 50 hp, heroes can pass these, creeps cant and are forced to atack the trees.
2 - Medium tree - 100 hp, heroes/creeps can only pass after killing the trees.
3 - Large tree - 150 hp, heroes/creeps can only pass after killing the trees.
For a price of 50 mana, lets you to plant a tree!
A Sappling sack (new item) costs some 1500 gold
Runes of the Blight (1 tree = 1 rune)
50 mp/tree regardless of level.
Goal of the item:
A fun item with an ability to block out lanes, stalling the enemy. Perfect for ambushes.
Limiting factors are gold an mana, so that the person cant fill the whole map with trees.