_The stamens are never more than 4_, the posterior one _remaining
undeveloped_; they _usually have free anthers_ which generally project
considerably (Fig. 599). The ovary is unilocular with 1 _pendulous_
ovule and bears 1 _undivided style_; fruit a nut with 1 _seed,
containing endosperm_ and with the radicle turned _upwards_ (Fig. 597).
The flowers do not always open in centripetal order, a fact
which may be observed especially in the Dipsacaceæ, in which a
zone of flowers round the centre of the capitulum opens first,
and the flowering then proceeds both upwards and downwards
(Fig. 598). This has probably some connection with the fact
that the capitulum has arisen from the coalescence of several
dichasial inflorescences. In species of _Scabiosa_ the flowers
open simultaneously at the circumference, or in a zone at the
centre.--The morphological explanation of the “_epicalyx_”
is not quite certain; in all probability it is formed from
two united bracteoles, for an “epicalyx” is distinctly formed
in this way in one of the Valerianaceæ, _Phyllactis_.--The
_ray-flowers_ are larger and more irregular, labiate or
ligulate, than the disc-flowers, yet not in so high a degree as
in the Compositæ.
=A.= A scarious bract to each flower. _Scabiosa_ has a 5-lobed
corolla; the “epicalyx” has a dry, scarious, often finally large
collar, and the true calyx is formed of long bristles (generally 5)
(Fig. 597). _Succisa pratensis_ (Devil’s-bit) has a 4-lobed corolla,
the collar of the “epicalyx” is herbaceous; the calyx as in the
preceding.--_Pterocephalus._--_Dipsacus_ (Teasel); large, spiny and
stiff-haired herbs with capitula, or short, thick spikes on which
both the involucral-leaves and bracts project considerably, and are
stiff and spinose (Fig. 598). The “epicalyx” has short teeth, or is
almost entire. ~The leaves of the stem unite together in pairs, so
that shallow cups are formed round the stems in which rain-water may
collect.--_Cephalaria._--_Morina_: the flowers are falsely verticillate
as in the Labiatæ; the calyx has 2 laterally-placed, entire, or
emarginate lobes; 2 stamens, or 2 large and 2 small ones.~
=B.= Bristles, but _no_ true bract to each flower. _Knautia_; the
corolla is 4-partite, the calyx cup-like, with many bristles or teeth
on the edge.
POLLINATION is in many species effected by insects. The
honey is secreted by a ring round the base of the style. The
flowers in our native species are considerably protandrous.
Gynodiœcious flowers also occur.--150 species; especially in
the Mediterranean and the Orient; the order is not represented
in the South Sea Islands, Australia and America.--The heads of
the true Teasel (_Dips. fullonum_) are used for carding wool, on
account of the elastic bracts, which are hooked at the point.
The order has bitter properties; tanin, etc.; but no species are
used in medicine or the household.--_Scabiosa atropurpurea_,
etc., are used as ornamental plants.
Order 3. =Calyceraceæ.= This order resembles the Compositæ in
the valvate æstivation of the corolla and the more or less
united stamens, and the Dipsacaceæ in the undivided style,
pendulous ovule and endosperm. The calyx is frequently composed
of 5 distinct scales. An “epicalyx” is wanting.--20 species;
America.