Answer: I'm not 100% sure on this one but I think the difference is that the stalagmite will grow on the cave floors and the stalactites are the ones found hanging from the ceiling.
Explanation: I went to a cave once and asked my dad what the things were called and he told me what I told you, the stalagmites will be coming up and the stalactites will be hanging out.
HOPE THIS HELPED YOU OUT, SORRY IF IT DIDN'T MATE!!
