Monesia is the extract of the bark of Chrysophyllum Glyciphloeum (lit. gold leaf), a common Brazilian tree known locally as buranhem or guaranhem. It was employed and commercialized in Europe as a high quality tanning agent and also used in medicine as a gentle excitant of the stomach, improving the appetite and the digestive functions.
The photos are taken from the web page of the Smithsonian Tropical Research Institute and correspond to the species Chrysophyllum cainito. The logo of the project is based on the flower of this species.
Further information about monesia bark can be found here.
An overview of the different Chrysophyllum species is available here.