Noun | 1. | ![]() asterid dicot genus - genus of more or less advanced dicotyledonous herbs and some trees and shrubs aster family, Asteraceae, Compositae, family Asteraceae, family Compositae - plants with heads composed of many florets: aster; daisy; dandelion; goldenrod; marigold; lettuces; ragweed; sunflower; thistle; zinnia Ageratina altissima, Eupatorium rugosum, white sanicle, white snakeroot - American herb having flat-topped clusters of small white flower heads; reputedly a cause of trembles and milk sickness; sometimes placed in genus Eupatorium |