I dug through some old pictures I had from the last time I grew some peppers to see if I could make out any differences between the scorpion and fresno pepper plants.  All I could find were close-up shots of the peppers that don’t really show the plants.  This is a scorpion pepper.

This is a fresno pepper.

The shape, texture, and color of the leaves are very similar, the peppers seem to grow from the same spots on the plants.  I think I’m just going to have to wait until they grow actual peppers before I’ll be able to tell them apart.  I’m really annoyed with myself for not being more careful keeping these things organized.