Why these two?
From my stiff view there is not much out there.
Bixa orellana has an important place in our history, botanical and else. Our, meaning American aboriginals in the Caribbean and the continent.
Bixa has other virtues, you could find them out yourself. One is significant, it has no relatives at all, is the juananonly...Individual and group, all in one.
Guaiacum officinale is similar...lots of history, incredibly hard wood, the architectural beauty of the crown/branches/ bark, medicinal uses. Find out.
What is pertinent is the rarity of finding them in any context. Even though I have visited the spots where they
exist, I have never noticed the first one, before. I have known these Guaicaums as long as I can remember.