structural:reformatting, quality:corruption
Ecology

Asteraceae are especially common in open and dry environments. Many members of Asteraceae are pollinated by insects, which explains their value in attracting beneficial insects, but anemophily is also present (e.g. Ambrosia, Artemisia). There are many apomictic species in the family.

Seeds are ordinarily dispersed intact with the fruiting body, the cypsela. Anemochory (wind dispersal) is common, assisted by a hairy pappus. Epizoochory is another common method, in which the dispersal unit, a single cypsela (e.g. Bidens) or entire capitulum (e.g. Arctium) has hooks, spines or some structure to attach to the fur or plumage (or even clothes, as in the photo) of an animal just to fall off later far from its mother plant.

Some members of Asteraceae are economically important as weeds. Notable in the United States are Senecio jacobaea (ragwort), Senecio vulgaris (groundsel), and Taraxacum (dandelion). Some are invasive species in particular regions, often having been introduced by human agency. Examples include various tumbleweeds, Bidens, ragweeds, thistles, and dandelion. Dandelion was introduced into North America by European settlers who used the young leaves as a salad green. A number of species are toxic to grazing animals.