Erythroxylum (=Erythroxylon) is a genus of tropical flowering plants in the family Erythroxylaceae. Many of the approximately 200 species contain the drug cocaine; Erythroxylum coca, a native of South America, is the main commercial source of cocaine and of the mild stimulant coca tea. Another species, Erythroxylum vacciniifolium (also known as Catuaba) is used as an aphrodisiac in Brazilian drinks and herbal medicine.
Erythroxylum species are food sources for the larvae of some butterflies and moths, including Dalcera abrasa, which has been recorded on E. deciduum, and the species of Agrias.
The Erythroxylum genus and its species of cultivated coca were the subject of systematic study by ethnobotanist Timothy Plowman.