Bright funny!

At the beginning of the third class, the teacher decided to come up with something interesting.
He offered to children to buy pots and put them on a plant.
And then the grown plants to take home.
Children chosen pots in the form of clowns.
And they decided to plant cactus.
When several months passed and cacti grew up, the teacher asked the children not to take home pots and transplanted into them instead of cactus violet.
The children did so.

Do you know why the teacher does not allow children to take home pots with cacti?
Click on and you will see :))