I got a "Psychotria viridis" plant (likely psychotria alba but mislabeled) a few weeks ago. The plant had a single node at the bottom with 2 stems. When I received the plant the set of leaves on one individual stem had this white chalky residue on their exterior. I thought nothing of it at the time but it seems to have persisted. Does anyone know what this is and how to get rid of it?

Could you post some pictures?

My guess would be a fungus of some sort.
Wikipedia lists neem oil (comes from a tree), cinnamon essential oil, Rosemary oil, and others as natural fungicides.

I'll be posting pictures later when i'm home. Thank you, i'm glad I have some neem oil.