er lip, or
in other words the two lobes of the upper and the three of the lower
lip, reveal the real composition. So also does the alternation of these
five parts with those of the calyx outside. When the calyx is also
bilabiate, as in the Sage, this alternation gives three lobes or sepals
to the upper and two to the lower lip. Two forms of the labiate corolla
have been designated, viz.:--

_Ringent_ or _Gaping_, when the orifice is wide open, as in Fig. 256.

_Personate_ or _Masked_, when a protuberance or intrusion of the base of
the lower lip (called a _Palate_) projects over or closes the orifice,
as in Snapdragon and Toad-Flax, Fig. 257, 258.

[Illustration: Fig. 263. Corolla of a purple Gerardia laid open, showing
the four stamens; the cross shows where the fifth stamen would be, if
present.]

[Illustration: Fig. 264. Corolla, laid open, and stamens of Pentstemon
grandiflorus, with a sterile filament in the place of the fifth stamen,
and representing it.]

[Illustration: Fig. 265. Corolla of Catalpa laid open, displaying two
good stamens and three abortive ones or vestiges.]

266. There are all gradations between labiate and regular corollas. In
those of Gerardia, of some species of Pentstemon, and of Catalpa (Fig.
263-265), the labiate character is slight, but is manifest on close
inspection. In almost all such flowers the plan of five, which is
obvious or ascertainable in the calyx and corolla, is obscured in the
stamens by the abortion or suppression of one or three of their number.

[Illustration: Fig. 266. Two flower-heads of Chiccory.]

[Illustration: Fig. 267. One of them half cut away, better showing some
of the flowers.]

267. =Ligulate Corolla.= The ligulate or _Strap-shaped_ corolla mainly
belongs to the family of Compositae, 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: F