Kwasimukamba or Graman Quassi (also spelled Quacy, Kwasi and Quasi) (1692 – 12 March 1787 in Paramaribo) was a Surinamese healer, botanist, slave and later freedman of the 18th century, who is today best known for having given his name to the plant species quassia.
Kwasi's roots were among the Kwa speaking Akan people of present-day Ghana, but as a child he was enslaved and brought to the New World. As a slave in Suriname, a Dutch colony in South America, he participated in the wars against the Saramaka maroons as a scout and negotiator for the Dutch, and he lost his right ear during the fighting. For this reason the Surinamese maroons remember him as a traitor.
Kwasi worked as a healer of some renown, and fared so well that he was able to get his freedom and travel to the Netherlands. One of his remedies was a bitter tea that he used to treat infections by intestinal parasites, this concoction was based on the plant Quassia amara which Carl Linnaeus named after him, as the discoverer of its medicinal properties. Quassia continues to be used in industrially produced medicines against intestinal parasites today. In contemporary accounts he was described as "one of the most extraordinary black men in Suriname, and perhaps the world"