There are over 2,000 species of Euphorbia in the world, ranging from annual weeds to trees. Most originate in Africa and Madagascar, and a significant percentage of these are succulent. All contain latex and have a unique flower structure. Native Americans used the plant for many medicinal purposes including treatment of skin infections (applied on the skin) and gonorrhea (internally). Traditionally, Euphorbia species have been used internally as laxatives and externally for rheumatism and skin conditions. However, nearly all the Euphorbias are poisonous and exude an acrid milky fluid when broken. Euphorbia is stated to possess antitussive, antifungal and antitumor properties. There is mixed evidence showing euphorbia's effectiveness for chronic bronchitis, eczema, epilepsy and oral inflammation. Small doses tend to be expectorant and diaphoretic. Larger doses produce emesis (vomiting) usually without much pain or spasm, nausea or dizziness. The roots and leaves of euphorbia are a strong laxative. Petty spurge sap has traditionally been used as a wart cure.