Family Compositae, one of the largest plant families (also known as Asteraceae, daisy family, and aster family), which contains more than 1,100 genera and almost 20,000 species of herbaceous plants, shrubs, and trees, found throughout the world.
Though diverse in habit and habitat, composites tend to grow in sunlit places in temperate and subtropical regions. The family includes many garden ornamentals, including ageratum s, asters, chrysanthemum s, cosmos , dahlia s, marigold s, and zinnia s. Some genera include weeds such as dandelion , ragweed , and thistle . Artemisia , artichoke , endive , safflower , salsify , lettuce , and sunflower are important for the products derived from their flowers, seeds, leaves, roots, or tubers. Flower heads in this family are composed of many small flowers (florets) surrounded by bract s. Bell-shaped disk florets form the centre of each head; strap-shaped ray florets extend out like petals from the centre and are sometimes reflexed (bent back). Some species have flowers with only disk or only ray florets.