An order of flowering plants, division Magnoliophyta (Angiospermae), which gives its name to the subclass Asteridae in the class Magnoliopsida (dicotyledons). The Asterales have often been included in the order Campanulales, but they are perhaps more closely allied to the Rubiales and Dipsacales. The order consists of only the single very large family Asteraceae (Compositae), with about 20,000 species, occurring in nearly all parts of the world but most abundant and conspicuous in areas which are not densely forested.