Asteraceae is one of the largest angiosperms (flowering plants) families, with more than 1,620 genera and 23,600 species of herbaceous plants, shrubs, and trees distributed throughout the world, including various types of asters (daisies), arnica, chamomile, goldeneye, marigold, snakeroot, tansy, thistle, and wormwood.

The most obvious and outstanding general feature of Asteraceae is their composite flower heads that superficially resemble individual flowers. Each such head is ordinarily subtended by an involucre of small modified leaves (bracts).