German Chamomile is an interesting one to distill, you get a compound called chamazulene which is a fabulous blue colour.
The colour is actually an artefact from the steam distillation of matricine.
Or the related Scentless Mayweed,
Tripleurospermum inodorum (a weed in many countries) which contains matricaria ester. It has no fragrance but it is simple to isolate from crystallisation from hexane and it is a very unusual substance