THE ORDER ONAGRACEÆ: ILLUSTRATED BY THE DIFFERENT KINDS OF FUCHSIA;
ŒNOTHERA, OR THE EVENING TREE-PRIMROSE; GODETIA; EPILOBIUM, OR THE
FRENCH WILLOW-HERB; AND CLARKIA.
The type of this order is considered to be the common evening
Tree-primrose (_Œnothera biennis_), and it takes its name from
_Onagra_, the name given by Tournefort to the genus. The Fuchsia seems
so unlike the Œnothera, that it appears difficult to any but a botanist
to trace the connexion between them; but, botanically, they agree in
the position of the ovary, which in both is so placed as to seem rather
to belong to the flower-stalk than to the flower; and this peculiarity
is found in all the genera included in the order. The parts of the
flowers are also always either two, four, eight, or twelve; as, for
example, there are four petals and eight stamens in both the Fuchsia
and the Œnothera.
THE GENUS FUCHSIA.
Little more than fifty years ago, the first Fuchsia was introduced
into England; and we are told that small plants of it were sold at
a guinea each. Now more than twenty species, and innumerable hybrids
and varieties, are in common cultivation, and we find them not only in
greenhouses and windows, but planted in the open air as common border
shrubs. The first Fuchsia seen in England was _F. coccinea_, introduced
in 1788; and this species is still common in our gardens. It was
followed about 1796 by _F. lycoides_; and after that no other species
was introduced till 1821, since when a full tide of Fuchsias has kept
pouring in upon our gardens, from the different parts of Mexico, South
America, and New Zealand, to the present time.
All the Fuchsias were formerly divided into two sections; the plants
in one of which having the stamens and pistil concealed, and those in
the other having the stamens and style exserted, that is, projecting
beyond the other parts of the flower. The first division comprises
all the small-flowered kinds; such as _F. microphylla_, _thymifolia_,
_cylindracea_, and _bacillaris_, all which have the lobes of the calyx
short, and the petals partially concealed. _F. parviflora_ belongs to
this division, but it is distinguished by its glaucous leaves with an
entire margin; and _F. lycoides_ is also included in it; though this
last seems to form the connecting link between the two sections, as
both its petals and its style and stamens are partially exposed. The
second division comprises all the kinds which have long projecting
stamens.
As the general arrangement of the parts of the flower is nearly the
same in both divisions, _fig._ 31, which represents the section of a
flower of _F. cylindracea_, from the _Botanical Register_, will give
my readers a clear idea of the botanical construction of the Fuchsia.
In this figure, _a_ shows two cells of the ovary (which when entire
is four-celled, opening when ripe into four valves), with the seeds
attached to a central placenta. This ovary is surrounded and protected
by the dilated disk, which also serves as a lining to the tubular part
of the calyx, _b_. The anthers, in this division, have very short
filaments, which are inserted in the lining of the calyx, as shown at
_c_; _d_ is the style, which, in fact, consists of four styles united
together, and which divides near the apex into four stigmas; _e e_ are
two of the four lobes of the calyx; and _f_ is one of the four petals.
[Illustration: FIG. 31.—SECTION OF THE FLOWER OF FUCHSIA CYLINDRACEA.]
[Illustration: FIG. 32.—FUCHSIA DISCOLOR.]
In the second division, of which _F. coccinea_ may be considered
the type, the calyx and the corolla are of different colours. In
_fig._ 32, which shows a flower of _F. discolor_, the Port Famine
Fuchsia, the calyx (_a_) is scarlet and the most ornamental part of
the flower, while the petals (_b_) are purple, and wrapped over each
other. The ovary (_c_) is green, and when the petals and calyx fall
off, it swells into a berry, which becomes of a dark purple when ripe.
_F. globosa_ differs from _F. coccinea_ in the flowers being shorter
and more globose, while the limb of the calyx curves inward. In _F.
macrostemma_, a well-known Fuchsia, the lobes of the limb of the
calyx are, on the contrary, recurved, that is, turned backwards. This
formation is common, more or less, to several other species. In _F.
excorticata_, the New Zealand Fuchsia, there is a large fleshy knot at
the base of the calyx, and strong ribs running up the lobes; the calyx
is green when young, but it afterwards becomes crimson; and the petals
are very small. This species is so different from the others, that it
was at first described as a new genus, under the name of Skinnera.
The calyx is green at first, but it afterwards becomes crimson. _F.
arborea_ has pale-purplish flowers, and, like _F. lycoides_, forms a
connecting link between the two sections, the stamens being only a
little exserted, and the petals hidden.
_F. radicans_, the only Fuchsia yet discovered with a creeping stem,
which was introduced in 1841, belongs to this division.
These sections include all the Fuchsias known in British gardens
previously to 1835; but since that period, two kinds have been
introduced, which belong to a third division. These are _F. fulgens_
and _F. corymbiflora_. In these plants the tube of the calyx is about
two inches long, and the lobes are very short. The petals are also
short, and scarlet or deep-rose colour, though not exactly of the same
hue as the calyx. The leaves are large, with the midribs and veins red;
and the branches and pedicels are also of a dark reddish purple.
THE GENUS ŒNOTHERA.
In the description of the botanical construction of the Fuchsia, my
readers may have observed, that the ovary is placed below the calyx,
and quite distinct from it. The same construction is still more visible
in the Œnothera, as the tube of the calyx is very slender, and often
more than two inches long, while the ovary is often vase-shaped, and
of large size. The calyx of _Œnothera biennis_, the common Evening or
Tree Primrose, consists of four sepals growing together in the lower
part, so as to form a long tube (_a_ in _fig._ 33), and with the upper
part or limb generally in two segments (b), which are bent quite back
when the corolla expands, and which may be easily divided with a pin
into four. There are four petals in the corolla (_c_), and they are
placed so as to wrap over each other at the base. The calyx is lined
with the dilated receptacle, and in this lining are inserted the
filaments of the eight stamens (as shown at _d_); the stamens having
versatile anthers, that is, anthers attached to the filament by the
middle, so as to quiver at every breath. The pollen contained in the
cells of these anthers feels clammy when touched; and its particles,
when magnified, will be found to be triangular, and connected by
small threads, a form of construction peculiar to this genus and its
allies. The style is long, and the stigma is four-cleft. The ovary (_e
e_) is situated at the base of the calyx, and when ripe, it becomes
a four-celled dry capsule, which bursts into four valves, opening at
top to discharge the seed. The seeds, when young, are attached to the
central placenta, and they are quite free from hair or wool of any kind.
[Illustration: FIG. 33.—THE EVENING PRIMROSE (_Œnothera biennis_).]
The genus Œnothera being a very extensive one, it has been divided
by M. Spach, a German botanist residing in Paris, into fourteen new
genera; but only one, or at most two, of these genera have been
adopted by other botanists. One of these Godetia, which embraces all
the purple-flowered kinds, has been divided from Œnothera, on account
of a slight feathery appearance on the seeds; whereas the seeds of
the true yellow-flowered Œnotheras are naked, that is, without the
slightest appearance of any feathery substance or wing. The other
genus, Boisduvalia _Spach_, includes only two species, both with pink
flowers, which are very seldom seen in British gardens. The generic
mark of distinction consists in four of the stamens in these species
being shorter than the other four; whereas in the true Œnotheras all
the eight stamens are of equal length. As M. Spach’s other genera
have not been adopted by any British botanist, it is not worth while
troubling my readers with the distinctions between them. The flowers of
the yellow Œnotheras only open in the evening, or in cloudy weather;
but those of the purple kinds, or Godetias, remain open all day. The
leaves in both kinds are alternate.
THE GENUS EPILOBIUM.
[Illustration: FIG. 34.—EPILOBIUM ROSEUM.]
This genus is well known, by the showy plant often seen in shrubberies,
called the French Willow-Herb—(_Epilobium angustifolium_), and the
English weed called Codlings-and-Cream (_E. hirsutum_). In this
genus, the tubular part of the calyx which incloses the ovary,
is quadrangular, as shown at _a_ in _fig._ 34, which represents
seed-vessels of _Epilobium roseum_, a very common weed in the
neighbourhood of London. The limb of the calyx is four-cleft, and the
corolla has four petals; and when these fall off, the ovary assumes
the appearance shown at _a_. The quadrangular form is retained by the
capsule, which, when it ripens, bursts open into the four valves (_b_),
and discharges the seed which was attached to the central placenta
(_c_); each seed being furnished with a little feathery tuft resembling
pappus, as shown in _fig._ 35. The genus Epilobium is divided into
two sections; the plants in one of which have irregular petals, the
stamens bent, and the stigma divided into four lobes, as in the French
Willow-Herb, and the other showy species; and the plants in the other
section having small flowers with regular petals, erect stamens, and
the stigma undivided.
[Illustration: FIG. 35.—SEED OF EPILOBIUM.]
THE GENUS CLARKIA.
The calyx in this genus is tubular, with the limb in two or four lobes,
as in Œnothera. The corolla is, however, very different, the four
petals being unguiculate or clawed; that is, so much narrower in the
lower part as to stand widely apart from each other; they are also
three lobed. The stamens are very different, only four of them being
perfect, and the anthers of the other four being wasted and destitute
of pollen; and the stigma is divided into four leaf-like lobes, very
different from those of all the other genera included in the order. The
capsule is cylindrical in shape, and furrowed on the outside; it is
four-celled, and when ripe, it bursts open by four valves. The seeds
are quite naked.
Among the other genera belonging to this order, I may mention the
following: _Gaura_, the petals of which are somewhat unguiculate,
like those of Clarkia, but not three-lobed as in that genus; the
segments of the limb of the calyx often adhere two together, so as
to appear three instead of four; the ovary is one-celled, and the
seeds naked: _Lopezia_, which has apparently five irregular petals,
though, on examination, one will be found to be a metamorphosed
stamen, a four-cleft calyx, two stamens, including the one converted
into a petal, and a globular, four-celled capsule: and _Circæa_, or
Enchanter’s Nightshade, which has the limb of the calyx apparently in
only two segments, and only two petals and two stamens; the capsule
is globular like that of _Lopezia_, but it is covered with very small
hooked bristles, and it is divided into only two cells, each containing
only one seed.