ig. 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.]

269. =Adnation, or Consolidation=, is the union of the members of parts
belonging to different circles of the flower (256). It is of course
understood that in this (as likewise in coalescence) the parts are not
formed and then conjoined, but are produced in union. They are born
united, as the term _adnate_ implies. To illustrate this kind of union,
take the accompanying series of flowers (Fig. 270-274), shown in
vertical section. In the first, Fig. 270, Flax-flower, there is no
adnation; sepals, petals, and stamens, are _free_ as well as distinct,
being separately borne on the receptacle, one circle within or above the
next; only the five pistils have their ovaries coalescent. In Fig. 271,
a Cherry-flower, the petals and stamens are borne on the throat of the
calyx-tube; that is, the sepals are coalescent into a cup, and the
petals and stamens are adnate to the inner face of this; in other
words, the sepals, petals, and stamens are all consolidated up to a
certain height. In Fig. 272, a Purslane-flower, the same parts are
adnate to or consolidated with the ovary up to its middle. In Fig. 273,
a Hawthorn-flower, the consolidation has extended over the whole ovary;
and petals and stamens are adnate to the calyx still further. In Fig.
274, a Cranberry-blossom, it is the same except that all the parts are
free at the same height; all seem to arise from the top of the ovary.

270. In botanical