267. =Ligulate Corolla.= The ligulate or _Strap-shaped_ corolla mainly belongs to the family of Compositæ, in which numerous small flowers are gathered into a head, within an involucre that imitates a calyx. It is best exemplified in the Dandelion and in Chiccory (Fig. 266). Each one of these straps or _Ligules_, looking like so many petals, is the corolla of a distinct flower: the base is a short tube, which opens out into the ligule: the five minute teeth at the end indicate the number of constituent petals. So this is a kind of gamopetalous corolla, which is open along one side nearly to the base, and outspread. The nature of such a corolla (and of the stamens also, to be explained in the next section) is illustrated by the flower of a Lobelia, Fig. 285. [Illustration: Fig. 268. Head of flowers of a Coreopsis, divided lengthwise.] 268. In Asters, Daisies, Sunflower, Coreopsis (Fig. 268), and the like, only the marginal (or _Ray_) corollas are ligulate; the rest (those of the _Disk_) are regularly gamopetalous, tubular, and five-lobed at summit; but they are small and individually inconspicuous, only the _ray-flowers_ making a show. In fact, those of Coreopsis and of Sunflower are simply for show, these ray-flowers being not only sterile, but _neutral_, that is, having neither stamens nor pistil. But in Asters, Daisies, Golden-rods, and the like, these ray-flowers are pistillate and fertile, serving therefore for seed-bearing as well as for show. Let it not be supposed that the show is useless. See Section XIII. [Illustration: Fig. 269. A slice of the preceding more enlarged, with one tubular perfect flower (_a_) left standing on the receptacle, with its bractlet or chaff (_b_), one ligulate and neutral ray-flower (_cc_) and part of another; _dd_, section of bracts or leaves of the involucre.]