Note: None of these are inside the Caraphas Cave / Bree Tree Ruins. They are all on TOP of the Caraphas Cave / Bree Tree Ruins.

Get the first & second quest items at wild herb patches near the having a hoe equipt.

Get the third quest item (Fire Flake Flower) from Fire Flake Flower bushes. They're blue bushes with pink flowers.

Get the fourth quest item (Flower that resembles white azalea) from the Silver Azalea bush. It's pretty close to the Fire Flake bushes.

Get the fifth quest item (herb that matches Kunta's hint) from a wild herb. It isn't in the Ruins but on top of the mountain. You need to follow the mountain shape and walk (or jump) to get to where you need to be in order to pick it up.

Get the sixth quest item (Everlasting Herb) on the second biggest island of the Lake Kaia with all the mobs on it. It's near a set of two trees. If you are at/below 40, you will have problems as the mobs are purple.

The last quest you talk with the Black Spirit to get another quest and then talk to someone in Florin.

The end!

If you are lazy or unable to obtain Everlasting Herb, then buy it from Market Place.
It works, since you just need to give the herb to the NPC