One of our brightest darners, known by the all green anterior lateral thoracic stripe. Unfortunately, Canada Darner may occasionally show similar coloration. The notch in the front of this stripe is usually more shallow or obtusely angled in Green-striped. Other differences are beyond the scope of this site.
It is subjective, but the author feels that patrolling or feeding Green Striped Darners are very bright, almost similar to Lance-tipped, while Canada Darners do not look that bright.