A genus of herbaceous plants and shrubs of the family Convolvulaceae, containing about 100 species mostly native to tropical America and typically having small alternate leaves and axillary flowers; (also evolvulus) a plant of this genus, which includes a number of species popular as garden plants.
Mid 18th century; earliest use found in John Berkenhout (?1730–1791), physician and writer. From scientific Latin Evolvulus, genus name (LinnaeusSpecies plantarum (ed. 2, 1762) I. 391) from classical Latin ēvolvere + -ulus, after scientific Latin Convolvulus convolvulus.