A large family, of wide geographic distribution, resembling the Sunflower Family and by some authors included in it. They are herbs, rarely trees, almost always with milky, acrid, or bitter juice; the leaves alternate or from the root; the flowers small and crowded in heads, with involucres, the bracts in one or several rows; the receptacle flat or flattish, sometimes naked or smooth, sometimes scaly, pitted or honeycombed; the flowers all perfect; the calyx- tube without pappus, or with pappus of scales or bristles, sometimes feathery; the corollas not of two sorts, like those of the Sunflower Family, but all with a strap-shaped border, usually five-toothed, and a short or long tube; the anthers united into a tube around the style, which is very slender and two-cleft or two-lobed; the ovary one-celled and inferior, developing info an akene.

There are several kinds of Ptiloria, of western and central North America.