_Galium_ (Cleavers) is almost destitute of a calyx; it has a
small _4-partite, rotate corolla_, 4 stamens, and 2 free styles.
The fruitlets are _nut-like_. The inflorescence is a paniculate
dichasium passing into helicoid cymes.--_Asperula_ (Woodruff) is
distinguished from the above by its salver- or funnel-shaped corolla.
1 style.--_Rubia_ (Madder, Figs. 587–590) has almost the same form of
corolla as _Galium_, but (most frequently) a _5-merous flower_, and the
fruitlets are “_drupes_.” ~_Sherardia_ (Field Madder); the flowers are
clustered in closely arranged cymes surrounded by _an involucre_; _the
calyx has 6 distinct teeth_, while the number of petals and stamens is
4. The corolla is funnel-shaped.--_Vaillantia._ _Crucianella._~
The DISTRIBUTION OF SEEDS, in some instances, is promoted by
hooked appendages on the fruitlets (_e.g._ _Galium aparine_).
The small flowers of the Stellatæ are frequently collected
in compact inflorescences, and are therefore rendered more
conspicuous; slight protandry is found in some, self-pollination
in the species which are less conspicuous. Many species are
heterostylous. _Myrmecodia_, _Hydnophytum_, and other genera
have large tubers (hypocotyledonous stems), whose labyrinthine
cavities and passages are inhabited by ants.
About 4,500 species; tropical or sub-tropical except the
Stellatæ; especially American. The tropical ones are mostly
trees.--Several are ~OFFICINAL~ on account of the large
amount of _alkaloids_ and _glycosides_ which they contain. The
most important are the Cinchonas (_Cinchona calisaya_, _C.
succirubra_, _C. officinalis_, _C. micrantha_, etc.), whose bark
contains the well-known febrifuge and tonic, Quinine, Cinchonin,
etc.; Quinine is also found in _Exostemma_, _Ladenbergia_, and
_Remijia_. The root “Ipecacuanha” (an emetic) from _Cephaëlis
ipecacuanha_ (Brazils). Caffeine is officinal. The use of the
seeds of the coffee plant (“the beans”) was first known in
Europe in 1583.--There are only a few which contain _aromatic_
properties, principally among the Stellatæ (coumarin in
_Asperula odorata_, the Woodruff), in which group _colouring
materials_ are also found. The root and root-stalks of _Rubia
tinctorum_, the Madder (S. Eur., Orient., Fig. 587), were
formerly largely used for dyeing, but are now superseded by
the analine colours. Red dyes are also obtained from the roots
of species of _Asperula_ and _Galium_. Gambier is a splendid
colouring material, obtained from _Uncaria gambir_ (S.E. Asia),
which is used in dyeing and tanning.--The order does not furnish
many ornamental flowers.
Order 2. =Caprifoliaceæ.= This order agrees with the Rubiaceæ in having
opposite leaves and an epigynous flower, most frequently 5-merous
with the ordinary tetracyclic diagram, but in some species it is
zygomorphic; the corolla has imbricate æstivation, _carpels 3–5, most
frequently 3_ (not 2, which is the most usual number in the Rubiaceæ).
The fruit is generally a _berry_ or a _drupe_, but the most important,
and in any case most easily recognisable feature, is the _absence of
stipules_; in exceptional cases, where they are present, they are not
interpetiolar, and are most frequently small.--~The majority of plants
belonging to this order are shrubs or trees. Compound leaves sometimes
occur. Stipules only appear in a few species of _Lonicera_, _Sambucus_
and _Viburnum_; in the common Elder (_Sambucus nigra_) they are in
some instances glandular and small, but in other cases larger and more
leaf-like (upon long, well-developed shoots); in the Dwarf Elder (_S.
ebulus_) they have the normal leaf-like form; in _Viburnum opulus_ they
are present as narrow lobes at the base of the petiole; in others they
are completely absent. The leaves are frequently penninerved, rarely
palminerved. The calyx, as in the Stellatæ and Aggregatæ, is often very
insignificant.~
=1.= LONICEREÆ, HONEYSUCKLE GROUP. This has _campanulate or tubular
corollas_ which are often zygomorphic; in connection with the length of
the corolla the _style is long, filamentous_, and most frequently has a
large, capitate stigma. There are _several ovules_ in the loculi of the
ovary, and the fruit is most frequently a _berry_.
[Illustration: FIG. 591.--_Lonicera._]
_Lonicera_ (Honeysuckle). Shrubs, sometimes twiners. The corolla in
some species is considerably bilabiate (Fig. 591), with 4 lobes in
the upper lip, and 1 in the under lip, but in others more regular,
tubular, or campanulate. The flowers are either borne in capitate
inflorescences, which are compound and formed of closely compressed
3-flowered dichasia (sect. _Caprifolium_), or in dichasia with 2
flowers (the terminal flower is wanting). The ovaries and fruits
coalesce in some (sect. _Xylosteum_). ~The opposite leaves in some
species unite with each other and form a broad collar encircling the
stem (Fig. 591). Above the primary bud 1–2 accessory buds are often
found in the leaf-axils.--_Diervilla_ (_Weigelia_); with a 2-locular,
2-valved capsule.--_Symphoricarpus_ (Snowberry) has an almost regular,
funnel-shaped corolla; a peculiar feature is found in the ovary which
has 4 loculi, the 2 median having many ovules in 2 rows, all of which
are aborted; the 2 lateral ones, on the other hand, each have only 1
ovule which is developed. Different forms of leaves are frequently
found on the same branch; they are entire or lobed.~
=2.= SAMBUCEÆ, ELDER GROUP (Fig. 592). This has a _rotate_, _regular
corolla_, extrorse anthers, a very short and thick (or almost absent)
_style_, with tripartite stigmas, and only 1 pendulous ovule in each of
the 3 (-5) loculi of the ovary. The fruit is a “_drupe_” with 1–3 (-5)
stones. The inflorescence is made up of _cymes grouped in an umbel-like
arrangement_.
_Sambucus_ (Elder, Fig. 592) has _imparipinnate_ leaves and a “drupe”
with 3 (-5) _stones_. Between the calyx and the style a disc remains
on the apex of the fruit. _S. nigra_ with black fruit; _S. racemosa_
with red fruit; _S. ebulus_ is a perennial herb; the others are
woody.--_Viburnum_ (Guelder-rose) has _simple_ leaves (penninerved
or palminerved, entire, dentate or lobed), and a “drupe” with only 1
_stone_, which is compressed, cartilaginous, and parchment-like; 2 of
the loculi of the ovary are aborted. ~(In _V. opulus_ the marginal
flowers of the inflorescence are barren, and in that case their
corollas are generally specially large; the cultivated _Viburnum_ has
only barren flowers, with large corollas.)~
[Illustration: FIG. 592.--_Sambucus nigra_: _cor_ corolla; _s_
calyx.]
=3.= LINNÆEÆ. _Linnæa borealis_ (the only species) is an extreme form
of the order; it has a 2-flowered dichasium, funnel-shaped, slightly
bilabiate corollas (2/3); 4 didynamous stamens. Two of the 3 loculi of
the ovary have several ovules which are not developed, while the third
has only 1 ovule, which developes into a seed. The fruit is a nut,
which is enveloped by the two large bracteoles, which are covered by
sticky, glandular hairs, and serve as a means of distribution. It is a
small undershrub.
[_Adoxa_, which was formerly classed in this order, appears,
according to recent investigations, to be more properly placed
among the Saxifraginæ.]
In cases where the flowers are small, as in _Sambucus_ and
_Viburnum opulus_, they are rendered conspicuous by being
arranged in closely-packed inflorescences; they are massed
together and form large surfaces, and in the last named are
still more conspicuous on account of the barren, but large
ray-flowers, which are of service in this respect. Honey is
secreted in the nectaries at the base of the styles. In the
genera with rotate flowers, as _Viburnum_ and other Sambuceæ,
the honey lies so exposed and in such a thin layer, that only
flies and insects with short probosces can procure it; bees,
however, visit these flowers for the sake of the pollen. There
is hardly any nectar in the Elder; self-pollination frequently
takes place. The flowers of the Caprifoliaceæ, which, with their
long corolla-tube are adapted for evening-and night-flying
insects with long probosces, open in the evening, and at that
time give off their strongest scent.
DISTRIBUTION. 230 species; especially outside the Tropics in the
Northern Hemisphere. In this country they are found especially
in hedges and as under-shrubs.--OFFICINAL: the flowers and
fresh fruits of the Elder (_S. nigra_), the fruits (“berries”)
being also used in the household. ORNAMENTAL SHRUBS: species of
_Lonicera_, _Symphoricarpus_, _Diervilla_, which are chiefly
from N. Am., _Abelia_ and _Viburnum_.