Never fear! You do not need a chemistry book to understand this film (German language, English subtitles).
Showing a bunch of beautiful sundew species and hybrids, we explain really briefly and clear why particular chemical ingredients of the sundews are not only interesting as cough medicine for homeopathy, but also as traits for taxonomy, in a manner as comprehensible for laypersons as possible.
The featured chemical analysis (TLC) is helpful for the description of novel species and gains an additional dimension by the fact that most true species produce only one naphthoquinone or none, while hybrids show the chemistry of both parents combined. That means, if the parents produce different quinones, the hybrid shows both of them and both parents as well as the hybrid can be distinguished chemically that way.