=B.= FRUIT A BERRY. _Solanum_ (Nightshade); rotate corolla (Fig.
559). The stamens have short filaments, the anthers stand erect,
close together round the style, like a cone in the centre of the
flower, and open by pores at the apex (Fig. 560). ~_S. tuberosum_
(the Potato-plant); the Potato-tuber is a swollen, underground
stem; the “eyes” are buds, situated in the axils of its scale-like,
quickly-perishing leaves.~--_Lycopersicum_ resembles _Solanum_ in
the flower, but the united anthers open by longitudinal clefts and
have an apical appendage. The cultivated species, _L. esculentum_
(Tomato), has often a higher number than 5 in the flower, and in the
fruit several loculi of unequal size.--_Physalis_ (Winter Cherry);
the calyx ultimately swells out in the form of a bladder, becomes
coloured, and loosely envelopes the spherical berry.--_Capsicum_
(Guinea Pepper-plant); some species have very large, irregular,
rather dry (red, yellow, black) berries, which are unilocular
in the upper part.--_Lycium_ (false Tea-plant); the corolla is
salver- or funnel-shaped; shrubs; often thorny.--_Atropa_ (_A.
belladonna_, Deadly Nightshade, Fig. 555); corolla campanulate;
the calyx projects beneath the spherical, black berry. The flowers
are borne singly.--_Mandragora_; (Mandrake); _Nicandra_ (ovary
often 5-locular).--~A small tropical group: CESTREÆ (_Cestrum_,
_Habrothamnus_, etc.) has an almost _straight_ embryo, which may
also be found _e.g_. in species of _Nicotiana_. Related to the
Scrophulariaceæ.~
About 1,500 species; the majority within the Tropics, outside
these limits especially in America. _Solanum nigrum_ is a common
weed.--_The Potato-plant_ (_Solanum tuberosum_), from Peru
and Chili, was introduced into Europe in 1584 by Sir Walter
Raleigh. (Potatoes = Batatos). The fruits of several serve as
_condiments_: Chilies or Pod-pepper (_Capsicum annuum_ and
_longum_), and the Cayenne-pepper (_C. baccatum_ and others),
whose fruits also are officinal, were brought to Europe from S.
America by Columbus, and are commonly cultivated in Tropical
America; _Lycopersicum esculentum_ (Tomato) and others from
Peru; _Solanum ovigerum_ (Egg-plant); _Solanum melongena_,
etc. _Poisonous_, _acrid_, _narcotic_ properties (alkaloids,
etc., solanine, nicotine, atropine, hyoscyamine) are found in
many: _Atropa belladonna_ (from S. Europe; the roots and leaves
are officinal); _Solanum dulcamara_ (Bitter-sweet; formerly
officinal), _S. toxicarium_ (Guiana); _Datura stramonium_ from
Asia (leaves and seeds officinal), _D. sanguinea_, _metel_,
_tatula_, and others; _Hyoscyamus_ (officinal: the leaves
and seeds of _H. niger_); _Nicotiana tabacum_ (Virginian
tobacco, officinal: the leaves), _N. rustica_ and others from
Trop. America (_Tobacco_ was introduced into Europe in 1560);
_Cestrum_-species. _Duboisia myoporoides_ (Australia); the
leaves contain _hyoscyamine_ and are used in medicine. A number
of species of these genera are ornamental plants.
Order 2. =Nolanaceæ.= These most resemble the Convolvulaceæ
in the corolla, but the Solanaceæ in their branching, and
leaf-arrangement (in pairs, etc.). The diagram is the same as
in _Nicandra_ with 5 carpels, but the fruits of this order
most frequently form, by invaginations in various directions,
an ovary (with 1 style) consisting of numerous and irregularly
grouped, 1-ovuled cells; the fruit is a schizocarp with many
1-seeded fruitlets.--_Nolana_ (Western S. America): a few are
ornamental plants.
Order 3. =Scrophulariaceæ.= The flower is hypogynous, ☿, _zygomorphic_,
with the usual type: S5, P5, A5, and G2, the latter placed _in the
median plane_; some genera have all 5 stamens developed (Fig. 562
_A_), but most frequently the posterior one is suppressed and the
flower becomes _didynamous_ (Fig. 562 _B_). The fruit, as in the
capsular-fruited Solanaceæ, is a bilocular, 2-valved _capsule_, with
a _thick, axile placenta_, and most often septicidal dehiscence
(Fig. 563 _C_). The _numerous seeds_ are not reniform as in many
Solanaceæ, and have a _straight, or only slightly curved embryo_, with
abundant endosperm (Fig. 563 _D_).--The majority are herbs; some are
arborescent; the leaves are opposite or scattered, but stipules are
wanting as in the whole family.
The Scrophulariaceæ are closely allied to the Solanaceæ, and
there is, properly speaking, no characteristic feature which
absolutely separates them. The somewhat irregular corolla, with
five stamens of unequal length in _Verbascum_, is also found
in _Hyoscyamus_; curved and straight embryos are found in both
orders. The activation of the corolla in the Scrophulariaceæ is
_simple imbricate_, in the Solanaceæ most frequently _folded
imbricate_ (in _Atropa_ and those allied to it, imbricate
without folding). The genera (about 164) are distinguished
according to the form of the corolla, number of stamens,
inflorescence, arrangement of the leaves, etc. _Verbascum_
belongs to the most primitive 5-stamened forms, and from it
proceed a long series down to _Veronica_, with only two stamens
and most frequently the posterior sepal suppressed.
[Illustration: FIG. 562.--Diagrams. _A_ _Verbascum_; _B_
_Linaria_; _C_ _Veronica_.]
=1.= ANTIRRHINEÆ, SNAPDRAGON GROUP. This has most frequently a
descending æstivation of the petals (the posterior petals are outside
the lateral ones, which again enclose the anterior; Fig. 562 _A_, _B_).
The plants belonging to this group are not parasites.
=a.= =5-stamened.=--_Verbascum_ (Mullein, Fig. 563 _A_) has a slightly
irregular, rotate corolla; five stamens (frequently covered with woolly
hairs), of which the two anterior ones are the longer and differ
often also in other respects. ~The inflorescences are racemose, often
with several series of accessory dichasia in the axil of each primary
floral-leaf. The leaves are scattered and, together with the stems, are
often covered with a grey felt of branched hairs.~
[Illustration: FIG. 563.--_Verbascum thapsiforme._]
[Illustration: FIG. 564.--_Antirrhinum majus._ A flower, and the
upper lip of a flower with the stamens.]
[Illustration: FIG. 565.--_Scrophularia nodosa._ Protogynous
flower in various stages: _A_ ♀ stage; _g_ the stigma projecting
from the throat of the corolla; _B_ the same in longitudinal
section; _C_ ♂ stage, the stigma is bent down and its former
position occupied by the stamens; _s_ staminode; _g_ stigma; _d_
nectary.]
[Illustration: FIG. 566.--_Digitalis purpurea._]
=b.= =4-stamened, didynamous= (Fig. 564).--_Scrophularia_ (Fig-wort,
Fig. 565) has cymose inflorescences in a panicle; the corolla (Fig.
565) is urceolate, short two-lipped; the posterior stamens are present
as a scale below the upper lip of the corolla (Fig 565 _s_). ~_S.
nodosa_ has a tuberous rhizome.--_Pentstemon_; the posterior stamen is
barren and very long.~--_Antirrhinum_ (Snapdragon). The corolla (Fig.
564) is personate, _i.e._ bilabiate, but with the under lip arched
to such an extent that it meets the upper lip, closes the corolla
throat, and entirely conceals the stamens and style; the corolla-tube
is produced into a short pouch at the base on the anterior side. The
capsule is oblique and opens by 2–3 pores, formed by small, dentate
valves. In _Linaria_ (Toad-flax) the pouch is produced into a spur.
Sometimes there are traces of the posterior stamens. The capsule opens
by large pores (one for each loculus), produced by large, many-partite
valves. _L. vulgaris_ reproduces by suckers.--_Digitalis_ (Foxglove,
Fig. 566) has long racemes with drooping flowers; the posterior sepal
is small (a step towards complete suppression, as in _Veronica_); the
corolla is obliquely campanulate, and generally nearly 4-lobed, the
two posterior petals coalescing.--_Alonsoa_; _Nemesia_; _Chelone_;
_Herpestis_; _Mimulus_; _Torenia_; _Vandellia_; _Limosella_ (_L.
aquatica_, Mud-wort, native); _Scoparia_; _Capraria_; _Erinus_ (found
on the Roman Camp at Chesters, Northumberland, and supposed to have
been introduced from Spain by the Roman soldiers); _Celsia_ (near
_Verbascum_); _Maurandia_; _Lophospermum_; _Rhodochiton_; _Collinsia_;
_Nycterinia_, etc.
[Illustration: FIG. 567.-Flower of _Veronica_.]
=c.= =2-stamened.=--_Gratiola_ (Water-hyssop). 5-partite calyx.
The upper lip of the corolla is undivided or slightly bifid; the
two anterior stamens are either entirely absent or are reduced to
staminodes (a transition to _Veronica_).--_Veronica_ (Speedwell), most
frequently 4-partite calyx; 4-lobed, rotate, zygomorphic corolla with
2 perfect stamens and no trace of the others (Figs. 567, 562 _c_);
capsule with loculicidal dehiscence. _Calceolaria_; the corolla has two
slipper-like lips.
=2.= RHINANTHEÆ, YELLOW-RATTLE GROUP. Herbs, all of which (with
the exception of _Lathræa_) are annual _parasites_ with green
foliage-leaves. They attach themselves by haustoria to the roots of
other plants and draw nourishment from them. The majority turn black
when dried. Racemose inflorescences. In many the calyx is 4-partite,
the posterior sepal being absent, or very small. The corolla is
distinctly bilabiate (Fig. 568), with _most frequently ascending
æstiration_; in the majority it does not become detached at the
base, but by means of a ring-like cut some distance up the tube; 4
didynamous stamens; pollen-grains dry, easily falling out; the anthers
are often furnished at the base with bristles or hairs (Fig. 568)
which play a part in the pollination, the probosces of the insects,
being forcibly pushed against them, agitate the anthers and shake out
the pollen-grains. Capsule with loculicidal dehiscence.--_Euphrasia_
(Eye-bright), _Melampyrum_ (Cow-wheat), _Rhinanthus_ (Yellow-rattle),
_Odontites_ (Bartsia), _Pedicularis_ (Louse-wort), and _Lathrœa_
(Tooth-wort) all have native species. The last named is pale yellow,
or reddish (without chlorophyll); ~it is a parasite on the roots of
the Hazel, Beech and other shrubs, having an aerial stem, and an
underground, perennial rhizome, covered with opposite, scale-like,
more or less fleshy leaves with a number of internal glandular,
labyrinthine cavities. The inflorescence is a unilateral raceme. It
approaches _Gesneriaceæ_ in having a _unilocular_ ovary with two
parietal placentæ.~
[Illustration: FIG. 568.--_Euphrasia officinalis._ Flower of
the large and the small-flowered forms; showing the anthers and
stigmas.]
The mechanical contrivances for POLLINATION are so numerous
that no general principle can be laid down. Personate flowers,
like those of _Antirrhinum_ are only accessible to strong
insects, such as humble-bees, which can force themselves
between the two lips, and so become dusted with pollen on
the back. In _Euphrasia_ and other _Rhinantheæ_ the insects
become covered with smooth, powdery pollen when they shake
the anther-apparatus in touching the hairs and bristles
mentioned above. _Scrophularia nodosa_ is protogynous (Fig.
565). _Digitalis purpurea_, however, is protandrous. _Mimulus
luteus_ and some others have sensitive stigmatic lobes, which
shut up on being touched. The _Veronica_-species constitute
a series, from large-flowered down to small-flowered forms,
and parallel with them are found various gradations from
insect-to self-pollination. In some (as _Euphrasia officinalis_,
_Rhinanthus crista galli_) there are two kinds of flowers:
large, which are pollinated by insects, and small, which are
self-pollinated (Fig. 568). _Lathræa squamaria_ (Tooth-wort)
is a protogynous spring-flowering plant, largely visited by
humble-bees. Others have cleistogamic flowers. _Nycterinia
capensis_ opens its flowers at night.
2,000 species; chiefly from the Temp. OFFICINAL: _Digitalis
purpurea_ (the leaves; Europe), a poisonous plant. _Verbascum
thapsus_ and _thapsiforme_, _Veronica officinalis_ (“Herba V.”),
_Gratiola officinalis_ (“Herba”) have medicinal uses. The whole
of the Scrophulariaceæ are more or less suspicious, if not
actually poisonous, and none serve as food. Many are ORNAMENTAL
PLANTS: _Mimulus luteus_ (N. America), _Paulownia imperialis_
(the only species; in Japan; a tree), _Antirrhinum vulgare_ (S.
Eur.), _Linaria_, _Pentstemon_, _Veronica_, _Calceolaria_ (Peru,
Chili, etc.).
[Illustration: FIG. 569.--Leaf of _Utricularia vulgaris_, with
bladder. Median longitudinal section through a bladder containing
a _Cyclops_. At a a hair of the upper-lip, at _i_ 2 bristles
of the under-lip of the entrance (_a_, _b_); in the latter are
placed 4 bristles _h_; _k_ stalk of the bladder, in which is seen
a vascular bundle. (After Cohn.)]
Order 4. =Utriculariaceæ.= To this order belong only perennial,
_insectivorous_, _aquatic_, and _marsh-plants_ (200 species) with
a more or less characteristic appearance. They differ from the
Scrophulariaceæ, especially in having =2= stamens (the anterior) and
a _unilocular ovary_, with _free, central placenta_ (like that of the
Primulaceæ). For the rest the flower is distinctly bilabiate, both in
the calyx and corolla. Two-valved capsule; no endosperm.
_Pinguicula_ (Butter-wort) has a rosette of leaves close to the ground;
these are sticky, covered with glandular hairs, and roll round any
small insects which may be caught upon them; flowers solitary, terminal
on a long scape; calyx, 5-partite; corolla with spur. The embryo
germinates with 1 cotyledon.--_Utricularia_ (Bladder-wort). Our native
species are floating, _without roots_, with hair-like, divided leaves,
studded with peculiar bladders (in the Tropics there are terrestrial
species, with ordinary foliage). The bladders (Fig. 569) have an
aperture, closed by a valve opening inwards, so that small aquatic
animals are allowed to enter, but are not able to escape; they are
thus entrapped in the bladders, and are probably used as food. Calyx
bipartite; corolla personate with spur.
The _embryo_ of _Utricularia_ is very imperfect, scarcely
more than a spherical, cellular mass, with a few slight
leaf-rudiments. On the germination of _U. vulgaris_, several
bristle-like leaves develop into a compact rosette; the stem
then develops, and also the finely-divided, bladder-bearing
leaves. A primary root is not developed. The stems branch
copiously and in a very peculiar manner. The growing-point of
the stem is rolled spirally.--The stigmatic lobes are sensitive
and close on being touched; self-pollination often takes place,
however, in _Pinguicula_.
Order 5. =Gesneriaceæ.= The flower in this order may be both
_epigynous_ (_Gesnerieæ_) and _hypogynous_ (_Cyrtandreæ_),
but otherwise is nearly the same as in Scrophulariaceæ,
only that _the ovary is unilocular_, with 2 _parietal_,
often bifid, _placentæ_. Of the 5 stamens the posterior is
rudimentary, or (more rarely) entirely wanting, and the others
are didynamous (Cyrtandreæ have often only 2 stamens); their
anthers are generally glued into a quadrangular mass. The
majority are herbs with juicy stems, opposite, verticillate
or scattered leaves without stipules, often, like the stems,
thick and juicy, soft-haired or glabrous. The corollas are
often highly-coloured (scarlet, red-yellow, etc., and spotted
internally), large and magnificent, so that many species are
ornamental plants. GESNERIEÆ (often epigynous) have endosperm;
S. Am.--CYRTANDREÆ, hypogynous, without endosperm; Asia, S.
Africa.--_Streptocarpus_, neither the primary root nor primary
shoot attains development; one of the cotyledons dies, while the
other grows and becomes a very large foliage-leaf, from which
spring adventitious roots and adventitious inflorescences.
500 species. _Gloxinia_, _Achimenes_, _Gesneria_, _Alloplectus_,
_Tydæa_, _Columnea_, _Nægelia_, _Æschynanthus_, and others,
especially in the forests of tropical America. Some are
epiphytes on trees, others prefer the leaf-mould of the
forest and crevices of cliffs. Several genera have peculiar,
catkin-like, underground shoots, with scale-like compact leaves;
others have tubers.
_Orobanche_ (Broom-rape) is allied to this order as a
_parasitic_ form. It is a parasite on the roots of other
plants, not like _Lathræa_ by means of thin rootbranches with
haustoria, but growing with the base of its stem in close
contact with its host, and probably even often protruding a kind
of thallus into it, in a manner similar to the Loranthaceæ. Its
aerial shoots are not entirely destitute of chlorophyll, but
are not green; they only bear scale-leaves and terminate in a
raceme or spike-like inflorescence.--Some _Orobanche_-species
are detrimental to various cultivated plants (Hemp, Lucerne,
Tobacco, etc.). The flowers are strongly zygomorphic; the
posterior sepal is often wanting, and the anterior are united
to the two lateral ones. Ovary unilocular, as in Gesneraceæ,
with 2 or 4 parietal placentæ.--The exceedingly small seeds have
a very rudimentary embryo, formed of an ellipsoidal, cellular
mass, without indication of cotyledons or other organs.--About
100 species; especially in the Mediterranean region.
Order 6. =Bignoniaceæ.= 500 species; nearly all trees and
shrubs, and to a great extent lianes, climbing by tendrils
(modified leaves), which are sometimes terminated by a
special clasping apparatus. These lianes have, as a rule, an
_anomalous stem structure_, the wood being either divided
into four wedges at right angles to each other, separated
by four grooves filled with secondary wood-parenchyma, or a
greater number of wedges occur, by the cambium ceasing to
form wood in several places. The leaves are most frequently
opposite and compound; the flowers in the main are similar
to the didynamous Scrophulariaceæ, and especially resemble
those of _Digitalis purpurea_; they are bilabiate, large,
and beautiful, campanulate or trumpet-shaped, many of the
prettiest ornamental plants in the Tropics belonging to this
order. The fruit is most frequently a large, woody, 2-valved,
siliqua-like, septifragal capsule, whose valves separate from
the flat and broad partition-wall, which bears the large,
generally winged seeds: _Tecoma_; _Bignonia_.--In gardens:
_Catalpa syringæfolia_ (Trumpet-wood); _Tecoma radicans_
(from S. Am.).--“Palisander”-wood is from _Jacaranda_ (S.
Am.).--_Eccremocarpus_ (N. Am.) forms, by its unilocular
capsule, a transition to the Gesneriaceæ (_E. scaber_;
herbaceous).
_Crescentia_ is allied to this order; _C. cujete_ (Calabash) is
its best known species. The fruit (unilocular with 2 parietal
placentæ) is a very large, spherical or ellipsoidal berry, with
a firm, finally woody outer layer. After the removal of the
juicy interior, these are commonly used as drinking vessels in
Tropical America.
Order 7. =Pedaliaceæ.= _Sesamum_ (_orientale_ and _indicum_);
very important oil-plants, which from olden times have been
cultivated in tropical Asia and Africa for food and as medicinal
plants, and are now cultivated in America also. The seeds are
used as a raw material in the manufacture of soap in Europe.--To
this order also belong _Martynia_ and _Craniolaria_, which have
a long horned capsule and sensitive stigmas.--46 species.
Order 8. =Acanthaceæ.= 1,500 species; mostly erect, slender,
branched herbs or shrubs, rarely arborescent, especially in
S. Am. and Ind. The branches frequently have swollen nodes;
the leaves are _opposite_, penninerved, undivided, more or
less lanceolate or elliptical, and generally leave a distinct
scar when they fall off. Stipules are wanting. The flowers are
solitary or in dichasia, which are arranged in 4-rowed spikes
or racemes, each flower with its subtending bract, which may be
brightly coloured, and most frequently also with two bracteoles.
With regard to the corolla (which is often labiate, in any
case irregular, and frequently prettily coloured), the 2 or
4 didynamous stamens (of whose anthers one half is inserted
lower than the other, or suppressed) and the gynœceum, the
Acanthaceæ are true Personatæ, approaching most nearly to the
Scrophulariaceæ: they differ from the other orders especially in
the _fruit_, which is a bilocular, 2-valved, often elastically
dehiscing capsule, which never has more than 2 rows, and in some
only 2 seeds in each loculus, the seeds being often compressed
and borne on _strong_, _curved_ or _hook-like funicles_
(_retinacula_) which persist after dehiscence. _Embryo curved
without endosperm_; radicle pointed downwards.--Cleistogamic
flowers are found in several species. Cystoliths are common.
The following grow wild in Europe: _Acanthus_ (_spinosus_
and _mollis_, whose pinnatifid leaves served as models for
the capitals of the Corinthian columns). The posterior sepal
is the largest of all the leaves of the flower, and covers
the other parts like a helmet; the 2 anterior sepals are
united, and the two lateral ones are small and greenish; the
corolla has no upper-lip, but only a 3-lobed under-lip. The
anthers are bilocular; the filaments ultimately become very
firm.--_Justicia_, _Eranthemum_, _Goldfussia_, _Thunbergia_ (a
twiner), _Ruellia_, _Dicliptera_, etc.--Ornamental plants in
conservatories.
Order 9. =Plantaginaceæ= (=Plantains=). The flowers (Figs. 570, 571)
are regular, ☿, hypogynous, with a =4=-partite, persistent calyx,
a gamopetalous, _scarious_ corolla with =4= projecting lobes, =4=
stamens, incurved in the bud, later on projecting considerably, about
equal in length, and a bilocular ovary with _one_ long, filamentous,
_undivided_, _feathery_, papillose style (see Fig. 571). The ovary
is most frequently bilocular with 1–few ovules in each loculus. An
hypogynous disc is wanting. The fruit is a _pyxidium_ with 1–few
peltate seeds attached in each loculus (_Littorella_ is in several
respects an exception). All species are herbs, the majority with
leaf-rosettes near the ground, and the flowers in spikes or capitula.
The labiate-like flowers are in this case entirely concealed
under a regular, apparently 4-merous exterior. The structure of
the flower, however, is the same as in the _Scrophulariaceæ_,
only the reduction, which is found in _Veronica_ (compare Figs.
562 _C_, 567 with 570, 571), is also present in this instance
and the lobes are also more equally developed; the posterior
petal corresponds to the bilobed upper-lip; the posterior stamen
and the posterior sepal also are entirely wanting. In the
development of the flower there is no trace of posterior sepal
or stamen, and the posterior petal arises from one primordium,
but the two anterior sepals arise before the lateral ones. The
position of sepals and petals does not agree with that of a
true 4-merous flower, which is represented in Fig. 361 _E._ The
bracteoles are always suppressed in _Plantago_.
_Plantago_ (Plantain, Rib-grass). The foliage-leaves are most
frequently scattered, entire, with curved veins, arranged in a
rosette close to the ground on an unlimited rhizome; the spike-like
inflorescence is borne on a long scape; in some (_P. psyllium_) the
leaves are opposite on a stem with well-developed internodes, and
the inflorescences are borne in their axils. The order also presents
a transition from insect-pollinated to wind-pollinated flowers.
~The flowers are protogynous, wind-pollinated in _P. major_ and _P.
lanceolata_, partly also in the other species, but insect pollination
also occurs, and _P. media_ has three kinds of flowers, some of which
are adapted for wind-pollination (Fig. 571), others, with short
filaments, for insects.~ _Littorella lacustris_ (Shore-weed) is the
most reduced of the Plantaginaceæ: an aquatic plant with rosettes
of round, awl-like leaves and diclinous (monœcious) flowers. ~In the
axils of the foliage-leaves is a very short 3-flowered spike, formed by
2 sessile ♀-flowers, and above them a long-stalked ♂-flower; all the
flowers are lateral, the terminal one being absent, as in _Plantago_.
The ♂-flower is essentially the same as in _Plantago_, but the ♀-flower
has a scarious corolla, with a narrow, 3–4-dentate mouth, which closes
tightly round the nut-like fruit.~
[Illustration: FIGS. 570, 571.--_Plantago media._
FIG. 570.--Diagram of _Plantago media_.
FIG. 571.--Two different forms of the flower (magnified):
1, chiefly adapted for pollination by wind; 2, for
insect-pollination. _a_ The stigma; _b_ the calyx; _k_ the
corolla.]
The genus _Plantago_ constitutes nearly the entire
order (200 species). Some are widely distributed weeds
(_e.g._ _P. major_, “The white man’s footstep”). In
_P. psyllium_ (S. Eur.) the integument of the seeds is
mucilaginous, and swells considerably in water.