For your research it would be beneficial to talk to a Haitian doktè fèy (medicine man). You’ll learn a lot from them.There are also two books, about leaves and herbs from
Haiti, that you
could check out: Plant ak Pyebwa Tè DAyiti
by François Severin and Les plantes et
Les Legumes D’Haiti qui Guerissent by Arsène Pierre Noël
I only know about some leaves because my mom grows some of them. She can make tea for every type of ailments you can think of. Her mother was the same too. I am always surprised that she has a stash of so many varieties of leaves at home.
My mom has used fèy melis for treating migraines, cramps, and gas. It’s also used for calming effects, nervousness, insomnia and nightmares.
She has primarily used Fonbazen for gas, stomach problems, intestinal worms, and cramps. But she says it can be used for “cleaning” the stomach and flushing the kidneys. The boiled leaves can be uses in a compress (on the forehead or the temporal area) for treating headaches, nausea, and vertigo.
She has also boiled the leaves in a large cooking pot with water and used them for baths.