goldenrod, any species of the large genus Solidago of the family Asteraceae (aster family), chiefly North American weedy herbs. They have small yellow flowers clustered, often in panicles, along a wandlike stem. The few species that have white flowers are called silverrod. The goldenrods were, at one time, incorrectly considered a chief cause of hay fever, probably because they bloom in late summer and autumn, at the same time as the less conspicuous ragweeds. Goldenrods attracted short-lived commercial attention when Thomas Edison found that certain species contain latex. Some species (sometimes called dyer's-weed) have yielded a dye, and the leaves of many species have long been used for medicinal preparations and teas, whence the botanical name [Lat. solidare = to make whole]. The goldenrod adds beauty to fields, roadsides, and salt marshes in so many parts of the United States that it has been chosen as the state flower of Alabama, Kentucky, and Nebraska and has even been suggested for the national flower. Goldenrod is classified in the division Magnoliophyta, class Magnoliopsida, order Asterales, family Asteraceae.