Virginia Creeper - Cheating!

3 - leaved Virginia Creeper

Virginia creeper is supposed to have 5 leaflets in a group. Normally it does, but occasionally it gets "lazy" and only give out 3. Which is a problem for people trying to distinguish it from poison ivy, which always has the the leaflets. If you look closely at the photo you will notice that one of the leaves has four leaflets in a group and one has the full set of 5. 

Virginia creeper leaves also have one particular feature that poison ivy never has: where the veins meet the leaf edge, there are tiny points that almost look like thorns. If you see those, you are not looking at poison ivy.

See the thorn-like points on the bottom of this leaf:

points on Virginia creeper leaf