Chapter II: ACROGYNÆ. The apex of the stem or of certain branches is adapted (6)

It is worthy of remark that in _Betulaceæ_, _Corylaceæ_ and
_Quercus_ the ovules, and to some extent the loculi of the
ovary are not developed till after pollination, so that the
development of the pollen-tube proceeds very slowly. The
smallness of the flowers, the absence of honey, the dryness
and lightness of the pollen, the size of the stigma and the
abundance of hairs found on many stigmas are all adaptations for
wind-pollination. It is also an advantage that the flowers are
generally pollinated before the foliage-leaves are developed,
thus preventing the pollen being entangled by the leaves.

The two orders _Betulaceæ_ and _Corylaceæ_ mentioned here are
by other authors united into one order. [It is doubtful whether
these two should be retained in the family Quercifloræ, as
recent researches (p. 273) have shown that they differ from
the Cupuliferæ in many important points, and agree with the
Casuarinas in the fact that the pollen-tube enters the ovule
through the chalaza.]

Order 1. =Betulaceæ= (=Birches=). Monœcious, with thick, cylindrical, _compound_ ♂ and ♀ inflorescences (2- or 3-flowered dichasia in a spike with spirally-placed floral-leaves) (Figs. 324, 326, 328). When the perianth in the ♂-flower is completely developed, it is composed of 4 somewhat united leaves, which are placed opposite the 4 stamens (Figs. 325, 326 _A_). The female flowers are _naked_; the ovary is bilocular, with two styles and one _pendulous_ ovule in each loculus. The subtending floral-leaves unite with the bracteoles and form a 3–5-lobed cover-scale, which is not attached to the fruit (Figs. 325 _D_, 326 _B_). Fruit a _nut without cupule_ (see _Corylaceæ_ and _Cupuliferæ_). ~In the bud the leaves are flat. The stipules are deciduous. On germination the cotyledons are raised above the ground. Terminal buds are only found on old Alder trees; the Birch has sympodial branches.~

_Alnus_ (Alder) (Figs. 324–326). In the majority of species the ♂-and ♀-catkins are both developed in the year previous to their flowering, and pass the winter naked and bloom before the leaves expand. ♂-flower: 4 stamens. ♀-flower: the 5-lobed cover-scales of the ♀-catkin are woody and remain attached to the axis, so that the entire catkin when ripe resembles a small cone (Fig. 324 _b_). Each cover-scale supports two winged or wingless nuts. ~In the native species of Alder the buds are stalked (Fig. 324 _k_). The bud-scales are formed by the stipules of the lowest leaves.~

_Betula_ (Birch). The ♂-catkins, in the native species, appear in autumn, the ♀-catkins in the flowering year on leaf-bearing, short-lived shoots. ♂-flowers: 2 stamens, divided (Fig. 328 _A_). The 3-lobed cover-scales (Fig. 327 _a_) of the ♀-catkin are detached from the axis; each cover-scale supports 3 broadly winged nuts (_b_). ~The stem has cork with annual rings. The young twigs and leaves have aromatic resin glands.~

THE INFLORESCENCES OF THE ALDER.--In the axil of each
cover-scale [_b_ in the Figs] is situated, in the ♂-catkins
(Figs. 326 _A_, 325 _A-C_) a 3-flowered dichasium, the
flowers of which have a 4-partite perianth, the posterior
perianth-segments being sometimes almost suppressed, and 4
stamens with undivided filaments. In the ♀-catkin (Figs. 325
_D_, 326 _C_) a 2-flowered dichasium is found, the middle
flower being suppressed (indicated by a star in _C_). In both
instances the inflorescences have two bracteoles (α-β) and the
flowers borne in their axils have each one bracteole (β′), the
other one (α′) being suppressed and therefore in 326 _A_ and _C_
only represented by a dotted line; these four bracteoles unite
with the cover-scale (_b_) which supports the entire dichasium,
to form the 5-lobed “cone-scale” (Fig. 326 _B_) which in the
♀-catkin eventually becomes woody.

THE INFLORESCENCES OF THE BIRCH.--A 3-flowered dichasium is
situated in the axil of the cover-scale in both ♂-and ♀-catkins
(Fig. 328 _A_, _B_); only the central flower has bracteoles
(α-β) (the lateral flowers having no bracteoles), and these
bracteoles unite, as in the Alder, with the supporting
cover-scale (_b_), and form a three-lobed cone-scale (Fig. 327
_a_).

While the ♀-flower exactly resembles that of the Alder, the
reduction of the ♂-flower, already described in the Alder, is
carried further, so that often only the 2 median perianth-leaves
are developed (Fig. 328 _A_); there are also _only_ 2 stamens,
these being deeply cleft, while the other 2 are suppressed.

About 50 species; N. Temp.--Fossil-forms certainly occur in
the Oligocene. During the Glacial period the Dwarf-birch (_B.
nana_) extended over Europe; at the present time it is confined
to the moors and mountains of N. Europe and N. America and Asia.
Wind-pollinated.

USES.--Important forest trees. The bark contains tannic acid.
The tar of the Birch is used in the preparation of Russia
leather; whilst its spring sap is very saccharine, and is used
in some places for making a fermented drink. Its external bark
is used for roofing, for baskets, etc.

Order 2. =Corylaceæ= (=Hazel-nuts=). Monœcious. The ♂-catkins are long and cylindrical; the ♂-flowers are placed singly in the axil of the subtending-leaf (cover-scale); they are _naked_ and formed of a number of _divided_ stamens, which are partly united with the cover-scale, 4 in the Hazel, apparently 8 (Figs. 330 _A_, 329 _B_, _C_), more on the Hornbeam. The ♀-flowers have a very small, _superior_ perianth; in the axil of each cover-scale a 2-flowered dichasium (Fig. 329 _D_) is present, of which the central flower (* in Fig. 330 _B_) is suppressed. The gynœceum is bicarpellary as in the Birches; the ovary is bilocular, with two long styles (Fig. 329 _D-F_); the loculi have 1 (-2) ovules (Fig. 330 _B_). Each single ♀-flower and fruit is surrounded by a _leaf-like covering_, the _cupule_ (husk), which is _formed of three floral-leaves_ (namely, the bract of a lateral flower, and its own bracteoles; thus in Fig. 330 _B_, α, α′, β’ form the cupule for the left-hand flower, and β, α_[1}, β_[1}, the cupule for the right-hand).

_Corylus_ (Hazel-nut, Fig. 329). The long, cylindrical ♂-catkins pass the winter naked, 2–3 together, on short branches. The very small ♀-catkins are enclosed in buds, in which they pass the winter; these buds are situated in the axils of the fallen foliage-leaves, and it is only by their larger size that they may be distinguished from the ordinary foliage-buds. In spring the ♀-catkins are easily recognised by their red, projecting stigmas (Fig. 329 _A_). The cupule--the “husk”--is tubular, fringed, and envelopes the nut. ~The leaves are alternate and unsymmetrical, the external side being larger than the internal; this is connected with the vernation, the blade being conduplicate in the bud; the stipules are deciduous. The bud-scales are formed of stipules, the most internal having a leaf-blade attached to them which is suppressed in the external ones. The cotyledons remain underground on germination.~

_Carpinus_ (_C. betulus_, Hornbeam). The ♂-and ♀-catkins do not appear till the leaves are shooting. The ♀-catkin in this instance is also long and cylindrical. The cupule in _C. betulus_ is 3-lobed, and to a slight extent only embraces the base of the ribbed nut (Fig. 331); each lobe corresponds to a floral-leaf. ~Whilst the carpels are placed medianly in _Corylus_, in _Carpinus_, on the other hand, they are situated transversely, as in the case of the _Betulaceæ_. The lamina of the leaf is not conduplicate in the bud, but flat, and folded only along the lateral veins, which are also indicated in the form of the fully-developed leaf; otherwise the vegetative characters are essentially the same as in the Hazel. The cotyledons are aerial.--_Ostrya_ resembles the Hornbeam, but the cupule completely envelopes the nut, as a sac open at the apex (Eur., N. Am., Japan).~

N. Am., Asia, and Europe; 25 species.--Fossil forms in the
Oligocene. Wind-pollinated. USES. As timber (_Carpinus betulus_)
and firewood. The fruits of _C. avellana_ (ordinary Hazel-nut),
_C. tubulosa_ (Lambert’s nut) and _C. colurna_ (Turkish Filbert)
are edible.

Order 3. =Cupuliferæ.= Monœcious. The inflorescences make their appearance with the leaves, arising in the axils of the leaves of the same year. _A woody cupule_ furnished externally with scales or spines is _common_, and surrounds 1-several flowers (the cupule in the Corylaceæ never encloses more than a _single_ flower or fruit). The ♂-flower has a united perianth, which is, however, 4–6 partite, and encloses an indefinite number of undivided stamens. The ♀-flower has a _superior, 6-merous_ perianth (3 + 3, compare Figs. 332 _D_, 334); the gynœceum is formed of 3 (or in _Castanea_ 4–6) carpels with a corresponding number of stigmas (Figs. 332 _D_, _H_; 334, 335); and the ovary has at the base 3 (-6) loculi (Fig. 333), each of which has 2 pendulous anatropous ovules; the fruit is a one-seeded nut (Figs. 332 _H_, 336).

The cupule of the Cupuliferæ, according to the opinion of Eichler, is formed by united bracteoles, (compare Fig. 333, where the four valves in the cupule of Castanea are considered as bracteoles of the lateral flowers of the dichasium); according to another view (see Prantl, in Engler’s _Bot. Jahrb._, viii., 1889), it is a ring-like axial outgrowth independent of the bracteoles of the flower, whose scales and spines are floral-leaves. The cupule in the Oak only encloses the base of the fruit, but in the Eating-chestnut and Beech the fruit is completely enclosed, and consequently the cupule must divide into a number of valves (generally 4) to allow the fruit to escape. In the 3-flowered dichasia of _Pasania_, Sect. Eupasania (Trop. Ind.), each individual flower has its own cupule of the same structure and development as in _Quercus_; and, moreover, each group of flowers has externally the typical six bracteoles.

_Castanea_ (Eating-chestnut, Fig. 332). The catkins are erect (_A_), cylindrical, with the ♀ at the base and the ♂ at the top, or some are entirely ♂ and _composed of small dichasia_. The _cupule_ (_C_, _F_) is 4-_valved_, provided with spines, and entirely envelops the 3 _nuts_; it is already developed at the time of flowering.--~♂-flowers are most frequently borne in 7-flowered dichasia, and have a well developed perianth, most frequently consisting of 6 leaves in two whorls (Fig. 332 _B_), and a large number of stamens. ♀-flowers are most frequently borne in 3-flowered dichasia (Figs. 332 _C_, 333); the letters in Fig. 333 indicate the older theory, according to which the 4 bracteoles (α′-β′) of the two lateral flowers are thick and united into a single 4-valved, _woody cupule_, which surrounds the 3 nuts, and is furnished externally with spines; the spines are well developed hair-structures.--6 carpels in two whorls.--The leaves in the vertical shoots have a divergence of 2/5, 3/8, 5/13; on the horizontal shoots they are alternate. The cotyledons remain underground on germination.~

_Fagus_ (Beech). The ♂-catkins are pendulous, capitate; the ♂-flowers have an obliquely bell-shaped, fringed perianth, with 6–20 stamens. ♀-catkins erect, 2-flowered, borne singly in the axil of foliage-leaves of the same year; the ♀-flower has a gynœceum formed of 3 carpels, bearing an epigynous, 6-leaved perianth (Fig. 334). In this genus _the dichasium has only 2 flowers_, the central one being suppressed. _The cupule contains_, therefore, only 2 triangular nuts (“mast”). ~All the shoots have the leaves arranged in two rows; the rows are on the underside, being only about 90° distant from each other; the buds on the other hand approach each other towards the upper side. The bud-scales are stipules without laminæ; in vernation the laminæ are folded along the lateral ribs, the upper lateral portion being the largest (as in Hornbeam and Chestnut). The cotyledons are folded, and at germination are aerial, large, and reniform. 4 species (Europe, Japan, N. Am.)--_Nothofagus_ (S. Am., New Zealand, S. Austr.)~

_Quercus_ (Oak, Fig. 335). Catkins simple. ♂-catkins long, thin, _pendulous_, few-flowered. ♀-catkins erect; the cupule is _cup-like_, _entire_, and encloses only the base of the solitary nut (“acorn”).--~The ♂-flower has a similar construction to that of the Chestnut. The ♀-catkin has not more than 5 flowers (single-flowered dichasia, in which _only the central flower is developed_). The scales on the cupules are no doubt leaf-structures in this case also. According to another theory, the scales are hair-structures; they arise on the internal face of the young cupule apparently in descending, but really in ascending order. The rim of the cupule gradually expands. In the ♀-flower (Fig. 335) the loculi of the gynœceum, together with the ovules, are not developed until _after_ pollination.--The leaves in all cases have a divergence of 2/5; the lowermost leaves on the shoots are reduced to stipules which serve as the bud-scales (5 rows). The laminæ are conduplicate, as in _Corylus_, and the external side is the broadest. The cotyledons are fleshy and remain underground. 200 species.--_Pasania_ (100 species).~

368 species, in temperate climates, especially in Europe and
N. America. Authenticated forests have been found in the
Oligocene. The Beech has one species, _Fagus sylvatica_, in
Europe; it is a most important forest tree (in Denmark the most
important) and reaches its most northern limit near Alvesund
in Norway (60° N.L.), its northern boundary line passing
from Alvesund in a zig-zag line through Ludwigsort, south
of Königsberg, in Prussia, towards the Crimea. According to
Steenstrup and Vaupell, the Beech did not make its appearance
in Denmark until a comparatively recent time, the Oak then
being partially supplanted. Other species of Beech are found
in N. America and Japan. Several species of _Nothofagus_
occur in the South West of S. America, and in the colder
regions of the southern hemisphere. The Oaks grow especially
in temperate regions, _e.g._ in Western Asia, N. America,
and the mountains of Mexico. Evergreen species are found in
Tropical Asia, Himalaya, Japan and the Mediterranean region.
In this country there is one species of Oak (_Q. robur_), of
which there are three varieties (_Q. pedunculata, intermedia,
sessiliflora_). The Eating-chestnut is found in the South of
Europe, but is cultivated in the midland and southern counties
of England.--USES. The wood of these trees is very useful as
timber. The wood of _Q. tinctoria_ has a yellow colouring
matter (Quercitron-wood). The bark of the Oak contains a large
quantity of tannic acid, and is used for tanning; for this
purpose also the cupules of _Q. vallonea_, _ægilops_, _græca_,
and others from the Eastern Mediterranean, are used under the
name of “Valloons.” The Cork-oak (_Q. suber_; S.W. Europe) is
the most important tree from which cork is obtained, its bark
being very largely developed and stripped for cork. Gall-nuts
are found on many species; those of _Q. lusitanica_, var.
_infectoria_ (Eastern Mediterranean) are officinal, and likewise
the fruits (acorns) and the bark of _Quercus pedunculata_ and
_sessiliflora_. Oil is obtained from the Beech “mast.” The nuts
of the Chestnut tree are edible.

Family 4. =Juglandifloræ.=

This family resembles the Quercifloræ in the catkin-like inflorescences, the imperfect, _unisexual_ flowers, the epigynous perianth and the woody shoots with scattered leaves, etc., though it is in other respects very dissimilar; one point of difference is the presence of _aromatic_ compounds, but a more important divergence is found in the structure of the gynœceum, which is formed of two carpels with _one loculus_ and has one _basal_, _orthotropous and erect_ ovule, which, as in the Quercifloræ, does not become developed until after pollination; the fruit too is very different, being generally a _drupe_. _Endosperm absent._

Order 1. =Juglandaceæ (Walnuts).= Leaves _scattered_, _imparipinnate_, rich in _aromatic_ compounds. _Stipules absent._ Flowers unisexual. _Monœcious._ The ♂-catkins are lateral, generally on naked branches of the previous year, cylindrical, pendulous, many-flowered; the two bracteoles and the 2–4-leaved perianth of the ♂-flower unite with the subtending bract; the ♂-flower has indefinite stamens (6–20 in _Juglans_, Fig. 337 _A-D_). The ♀-catkins are terminal, generally on branches of the same year, few-flowered (Fig. 337 _F_); the ♀-flowers have a _superior_, 4-leaved perianth, a bicarpellate gynœceum, two styles with stigmas on the internal surface. The ovary, bracteoles and bract all unite together (Fig. 337 _E_). The fruit is generally a green or black _drupe_,[34] whose flesh (outer soft portion) in _Carya_ and _Juglans_ ruptures more or less irregularly, and frees the stone (“Walnut”).--~The stone in _Juglans_ is divided internally by one true (Fig. 337 _H_) and by several false, low partition walls into several _incomplete_ compartments, so that the two large _cotyledons_ become lobed and incised to fit like a cast into the irregularities of the inner surface of the stone; the embryo is exendospermous and covered with a thin testa.--THE LEAF SCARS are large and cordate with 3 groups of vascular bundles. The PITH in _Juglans_ and _Pterocarya_ is divided into chambers. The stone ruptures, on germination, along the dorsal suture into 2 valves; the cotyledons remain underground. In _Juglans regia_ a long row of accessory buds is found on the lowest internode (epicotyl) above the axils of the cotyledons. _Pollination by the wind._ Both protogynous and protandrous examples of _Juglans regia_ occur.--33 species, mostly in temperate North America.--USES. Walnuts are obtained from _J. nigra_ and _regia_; Hickory from North American species of _Carya_. The oil-containing seeds of several species are edible. _Pterocarya_ and others are cultivated as ornamental plants.~

Order 2. =Myricaceæ=. To this order belong shrubs or trees which have penninerved, simple, at most lobed or pinnatifid leaves, with or without stipules, and with yellow, aromatic, resin glands (Fig. 338 _a_). The flowers, situated in catkin-like spikes, are unisexual and _naked_, and supported by scale-like floral-leaves. ♂-flower: 4–6 (–16) stamens with short filaments; ♀: generally situated singly. The gynœceum has a short style with 2 long stigmas, and unites with the bracteoles, which form wing-like outgrowths on the ripe drupe as in _Pterocarya_ in the Juglandaceæ (Fig. 338). Cotyledons fleshy (Fig. 338 _b_).--_Myrica_; _Comptonia_.

40 species; Temperate.--_Myrica gale_ (Sweet-gale, Bog-myrtle)
has been used in the preparation of beer (Sweet-willow beer)
on account of its resinous essential oil. _M. cerifera_ (N.
America) and species from the Cape, _M. quercifolia_ and others,
form wax on the fruit which is used in the preparation of
candles.

Family 5. =Urticifloræ.=

The flowers are regular, _hypogynous_, nearly always unisexual, _small_ and insignificant, with _single_, green perianth of 4–5 leaves. Stamens 4–5, _placed opposite_ the leaves of the perianth. Ovary formed of 1 or 2 carpels, most frequently _unilocular_, with one ovule (Fig. 340). The fruit is a _nut_, more rarely a drupe, with one seed, _generally endospermous_. ~The Nettles are the sole order in the family which has only one carpel (1 stigma); this turns the posterior side to the front (Fig. 340). The others have two carpels (2 stigmas) but the anterior only is fertile (Fig. 346) except in a few Ulmaceæ and Moraceæ.~

The majority are trees or shrubs with petiolated leaves, _stipulate_; _rough hairs_ are very frequently developed upon the leaves. The flowers are very often crowded together in the inflorescence, which is rarely catkin-like. Peculiar aggregations of fruits are found in some orders. _Latex_ and tough _bast_, which is used technically, are also frequently found. Cystoliths are found in the epidermis of many species of _Ficus_, _Urtica_, and others. ~_Wind-_ or _self-pollination_ is most common, as in the Quercifloræ and Juglandifloræ.~ In ~the Urticaceæ, _Morus_ and some others, the stamens lie incurved in the bud, and when ripe straighten themselves suddenly and elastically, and thus small clouds of pollen-grains are ejected with considerable violence on to the stigmas, which are often provided with brush-like hairs (Fig. 341). The formation of honey does not take place.~

Order 1. =Ulmaceæ= (=Elms=).--Trees or shrubs without latex. Leaves simple, arranged in two rows (divergence 1/2), oblique (the inner side, nearer the axis, being the larger), strongly penninerved, dentate, hispid; stipules deciduous. In opposition to the other Nettle-like plants the flowers are often ☿ with a united cup- or saucer-like, generally 4–(5)–6-divided perianth, and a corresponding or larger number of opposite _erect_ stamens. The gynœceum has two carpels (2 stigmas), generally one loculus with one pendulous, anatropous or amphitropous ovule,[35] seldom two loculi and 2 ovules. Fruit one-seeded (nut or drupe). Embryo without endosperm.

=A.= ULMEÆ. The fruit is a _winged nut_ (Fig. 339), the embryo straight, without endosperm. Anthers extrorse.--_Ulmus_ (Elm). The flowers are situated in inflorescences which develop from the lower buds of the shoot of the preceding year. ~The lowermost bud-scales are empty, the uppermost support either solitary flowers, or small, dichasial or unipared scorpioid inflorescences. The terminal bud on the vegetative shoot quickly falls off, and the upper lateral bud continues the growth sympodially. Flowering takes place before the leaf-buds open. The flowers are wind-pollinated and have no honey. Fossil species have been found in the Oligocene.~

20 species; North Temp. (2 species in this country). Important
as timber. The Cork-elm (_U. suberosa_) has a rather thick cork,
which, however, is of no technical use. The bast is used as
Lime-bast.

=B.= CELTIDEÆ. The fruit is a drupe, the embryo curved, with
folded or rolled up cotyledons, with or without endosperm.
The anthers are introrse. The flowers are borne on a shoot of
the same year. _Planera_ (N. America); _Zelkova_.--About 114
species; especially N. Temp., Trop.

Order 2. =Urticaceæ= (=Nettles=).--The majority of species are herbs with simple, stipulate leaves; they have _no latex_; _stinging hairs_ abundant. The flowers (Fig. 340) are _unisexual_, generally 2-merous and arranged _in clusters_, which are united into catkin-like inflorescences. The perianth is composed very often of 4 (2 + 2) free, or in the ♀-flowers generally united, green leaves; the 4 (2 + 2) stamens are opposite the perianth-leaves, the filaments are _bent inwards_ in the bud and throw themselves elastically towards the outside. The gynœceum has _one style_ and _one stigma_ (capitate or brush-like, Fig. 341); the ovary is unilocular, with _one orthotropous_, _erect_ ovule (all other orders of this family have inverted or curved ovules). Fruit, a nut or drupe. _Endosperm present_ (in _Urtica_ very little), oily. Embryo straight. ~The STINGING HAIRS are club-shaped, very turgid, and provided with a siliceous, brittle apex, which breaks off in an oblique direction and allows the poisonous cell-sap to be forced out. In many tropical Nettles this is so strong that it may produce partial paralysis. There is no rudiment of an ovary in the ♂-flowers (Fig. 340 A). The PERIANTH in the ♀-flower differs from that of the ♂ in having the two internal leaves generally much larger and enveloping the fruit (Fig. 340 _B_); it often happens that all the perianth-leaves are united to form a gamophyllous envelope. ☿-flowers may occur among the others.--THE INFLORESCENCES among our native species are dichasia, which become transformed into unilateral scorpioid cymes by the development of the bud of the 2nd bracteole. In _Parietaria_ they are more pressed together, and the floral-leaves at the same time are also raised on their axillary shoots to just beneath the flower. As a rule, not only in this order but also in those related to it, a small vegetative branch is situated in the axil of the foliage-leaf, and this bears an inflorescence on each side at its base.~

_Urtica_ (Nettle) has opposite leaves with distinct stipules and stinging hairs. The perianth-leaves of the ♀-flower are free (Fig. 340).--_Parietaria_ (Pellitory) has scattered leaves without large stipules, and stinging hairs are absent. The ♀-perianth is 4-toothed, flask- or bell-shaped.--~_Pilea_ is a tropical genus with trimerous, zygomorphic ♀-flowers, the posterior perianth-leaf being much larger than the two others, and more or less hood shaped.--The flower of _Forskohlea_ is the most reduced; the ♂-flower has only one stamen, and the ♀-as well as the ♂-flowers have a one-sided, tongue like perianth (?). _Pouzolzia._~

WIND-POLLINATED. The pollen is shot out of the anthers, when
they spring forward, and is caught by long stigmatic hairs.
_Parietaria diffusa_ is protogynous (Fig. 341).

500 species; chiefly in the Tropics, although the few species
which occur in Europe are represented by a much larger number
of individuals.--USES. The bast of the native species _Urtica
dioica_ and _urens_, of _U. cannabina_ (Siberia), etc.; of
_Boehmeria nivea_ “Ramié” and “China-grass” (from Sunda Is.,
China), and others, is used in the manufacture of muslin.

Order 3. =Moraceæ= (=Mulberries=). Nearly all trees or shrubs, seldom herbs, generally with latex. The leaves are scattered, and not infrequently lobed. The flowers are _unisexual_ (monœcious or diœcious) and arranged in catkin- or capitulum-like, compound inflorescences. Perianth-leaves 2–6, generally 4, with an equal number of stamens opposite to them, as in the Nettles. The ovary is 1–seldom 2-locular, and has 2 stigmas (it is thus formed from 2 carpels) seldom only one style with one stigma. One ovule in each loculus, more or less curved, and _pendulous_; micropyle directed upwards. Fruit usually a drupe. The embryo is generally curved inside the _fleshy endosperm_, or it is exendospermous.

=A.= MOREÆ. The filaments are incurved in the bud. Leaves folded in the bud--_Morus_ (Mulberry) (Figs. 342–344). Monœcious. The inflorescences are catkin-like in appearance, but in reality composed of many small dichasia. The flowers are similar to those of the Nettle, but with 2 carpels: in the ♂ with perianth 2 + 2, and stamens 2 + 2 (Fig. 342), in the ♀, perianth 2 + 2, and 2 carpels in regular alternation. The small drupes are enveloped by _the perianth, which eventually becomes fleshy_, and as all the flowers on the axis very accurately fit together, the collection of fruits is formed, which we call a Mulberry (Fig. 344). The leaves are folded in the buds, and have small stipules. ~The following are allied to _Morus_:--_Maclura_, _Broussonetia_ (the Paper-mulberry tree) which has spheroid ♀ inflorescences (made up of dichasia), etc.~

_Dorstenia_ presents an interesting transitional form to the Fig
in its flat, open, and, in some instances, lobed inflorescence
on which the ♂ and ♀ flowers are sunk in grooves. Indications
of a somewhat similar structure are found in certain Nettles,
the sympodial axes of the dichasia becoming flatly expanded. The
fruits are 1-seeded, but, nevertheless, spring open and eject
their seeds.

=B.= ARTOCARPEÆ. Filaments straight in the bud; foliage-leaves with convolute vernation. An interpetiolar leaf-sheath (ocrea) formed in the axil of each leaf by the connate stipules, covers the younger leaves as a hood. It falls off as the leaf expands, and leaves a ring-like scar on the stem.--_Ficus_ (the Fig). The inflorescence (the so-called syconus) has a pear-shaped, fleshy, but hollow axis, on the interior surface of which the flowers are situated (Fig. 345). It is a kind of capitulum, with a hollow receptacle, whose “involucral” leaves close over the entrance to the interior; it is not, however, a simple capitulum, but a coalescence of cymose inflorescences. The edible parts are the fleshy stem-portion and perianth-leaves. The ♂-flower has a 2–6 divided perianth, 1–2 (–6) stamens; the ♀-flower has an oblique ovary. The fruits are drupes, with thin flesh.--~Many species have aerial roots, and some live as epiphytes on trees. POLLINATION, in the edible Fig, is effected by a small Gall-wasp (_Cynips psenes_ L.), which lays its eggs in the Fig, and hence carries the pollen away. Even in very ancient times it was customary to hang infected wild Figs on the branches of cultivated ones, so that the young Gall-wasps, as they emerged, could immediately effect the pollination (caprification). _Ficus carica_, and other species, have two kinds of ♀-flowers, besides the ♂-flowers. One kind has a short style and no stigmatic hairs, and it is only in the ovaries of these that the wasps lay their eggs (gall-flowers); the other kind has a long style and well-developed stigmatic-hairs, but the wasps cannot reach their ovaries--these are “seed-flowers.” There are, moreover, two kinds of plants of _Ficus carica_; ♀-plants, which have only seed-flowers, and bear the edible Figs, and ♂-plants (called “Caprificus”), which bear inedible fruits, and have ♂-flowers at the upper part of the Fig, but gall-flowers at the base. [The Caprificus, at Naples, bears three crops of inedible Figs each year, viz. _Mamme_ (April), _Profichi_ (June), _Mamnoni_ (August). The ♂-flowers are produced especially in June, the first Figs being almost entirely ♀, and the last having but few ♂-flowers. Each crop produces a new generation of Fig-wasps. The female wasp enters the Figs on the Caprificus, and lays one egg in each flower, with the result that the flower developes into a kind of gall. The mother-wasp dies within the Fig. The male wasp is wingless; it bites a small passage into the ovaries containing the female wasps, and impregnates them; the female wasps then escape from the Fig, those in the _Profichi_ carrying pollen away with them as they pass out. They then enter another Fig, lay their eggs, and die. The edible Fig-tree similarly has three crops in the year, _Fiori di fico_, _Pedagnuoli_, _Cimaruoli_. The wasps, entering these Figs, are unable to lay their eggs in the ovary, but, nevertheless, they effect cross-pollination on entering the _Pedagnuoli_, which bear fertile seeds.]~

The flowers of _Brosimum_ are the most reduced. The perianth
is wanting, and the ♂-flower has only 1 stamen. _Cecropia_
(Trumpet-tree), in S. Am., has its pith divided into chambers;
these are inhabited by ants, which feed upon small food-bodies
formed on the swollen base of the petioles. The leaves are
petiolated, often shield-like, fringed or lobed, and sometimes
with white felted hairs. They serve as food for _Bradypus_
(the Sloth). _Sorocea_; _Castilloa_.

About 300 species exclusively in the warmer climates. The white
Mulberry (_M. alba_, from China, India, Mongolia) is cultivated
for the sake of its leaves, which are the indispensable food
for silkworms. The black Mulberry (_M. nigra_, W. Asia) is
cultivated for its fruits, which are used for the officinal
Mulberry juice. The ordinary Fig-tree (_Ficus carica_) is from
the Mediterranean. The fruit of the well-known Oriental Sycamore
(_F. sycomorus_) is edible. The Bread-fruit tree (_Artocarpus
incisa_) and the Jack (_A. integrifolia_) have their home in the
South Sea Islands, and are cultivated in tropical countries.
The Bread-fruit is morphologically the same as the Mulberry. It
has a very large, spheroid inflorescence, whose floral-leaves
and perianth become fleshy and united into one nutritious mass,
together with the axis, which is also fleshy. The milky juice
of the India-rubber tree (_Ficus elastica_, East Indies, a
common house-plant), and of _Castilloa elastica_ (Am.) is the
raw material of India-rubber. The milky juice of _Galactodendron
utile_ (Cow-tree, S. Am.) is saccharine and nutritious, but in
_Antiaris toxicaria_ (the Upas-tree, of Java) it is a strong
poison. The bast of the Paper-Mulberry tree (_Br. papyrifera_,
Eastern Asia); is used in Japan for paper. Shellac is obtained
from a small, hemipterous insect (_Coccus lacca_), which lives
upon _Ficus laccifera_ and _F. religiosa_ (the Bo-tree, sacred
to Buddha), E. India. The wood of _Maclura aurantica_ (Am.) has
a yellow colour, and is known as yellow Brazilian wood.

Order 4. =Cannabaceæ.= The plants which belong to this order are _aromatic herbs_, either annuals or perennials, _without latex_. Leaves _palminerved_, and more or less divided, hispid, and with free, persistent stipules. Flowers always _diœcious_; ♂-flowers in panicles, formed of dichasia, passing over into uniparous scorpioid cymes. They differ from the Nettles, particularly in the 5-leaved perianth of the ♂-flower, the 5 stamens (Fig. 346–351) with filaments _erect_ in the bud, and in the ♀-flower by the small, entire, cup-like perianth, which surrounds the base of the ovary (Fig. 346, p. 352). The ovary has two styles, or one divided into two, with two stigmas and a pendulous, curved ovule (Fig. 346 _B_, 352 _B_); the fruit is a nut; the _embryo_ is _curved_ (Hemp, Fig. 353), or rolled (Hop, Fig. 349), _without endosperm_.

Only 2 genera with 3 species (Asiatic), of which two are cultivated.--_Humulus lupulus_ (Hop, Figs. 347–349) is a twining, perennial plant, twisting to the right, with opposite, palmilobed, rough leaves, and large, interpetiolar stipules. The ♀-flowers are situated in closely-flowered, cone-like, compound inflorescences, with ultimately large, thin, imbricate floral-leaves (Fig. 348) which bear the yellow, glandular hairs, containing lupulin. ~This inflorescence is made up as follows:--The most external floral-leaves are situated in pairs, and are the persistent stipules of a leaf, the blade of which has become suppressed, or in any case is rudimentary. Such a pair of stipules supports 4 (2–6) flowers in a double uniparous cyme, whose central axis does not develope into a flower. The bracts of these flowers (bracteoles of the partial inflorescence) become, at maturity, very large, spathe-like, and, together with the stipules, produce a cone-like appearance.~

_Cannabis sativa_ (Hemp, Figs. 350–353) is an East Indian herb, with palmilobed leaves, and differs from the Hop in being annual, erect, and in having its leaves opposite at the base and scattered above. The ♀-inflorescence is not cone-like as in the Hop, but the flowers are similar in construction. ~The main difference is to be found in the axillary shoot, which was suppressed in the Hop, and is in the Hemp developed into a leaf-bearing shoot which on each side bears only one ♀-flower, and in the fact that the bracts are not so strongly developed.~

The “Hops” (the female inflorescences) are used in brewing,
and medicinally on account of the yellow glands which contain
lupulin. The Indian variety of _Cannabis sativa_ contains
an abundance of glandular hairs and resin. The withered
inflorescences are used in medicine and are officinal. The bast
of the stems of the Hemp is also used and the fat oil of the
seeds. In Oriental countries the entire plant is used in the
preparation of an intoxicating drink (haschisch), the narcotic
material being found in the glandular hairs.

Fig. 350, ♂-plant;

Fig. 351, ♂-flower;

Fig. 352, ♀-flower, entire and in longitudinal section;

Fig. 353, fruit in longitudinal section.]

Family 6. =Polygonifloræ.=

This family is on one side closely allied to the _Urticaceæ_ by its solitary, _basal_, _vertical_, and _straight_ ovule, and by the conical ocrea which envelopes the younger leaves in the bud, similar characters being present in the Urticaceæ. On the other side it is related to the Curvembryæ. The flowers are small, often _trimerous_, regular and slightly perigynous (~in _Chloranthaceæ_, if they properly belong to this family, and _Houttuynia_, more or less epigynous~). Syncarps are present in some Piperaceæ, but the fruit is generally a single fruit, one-seeded berry, nut or drupe. The leaves are generally scattered.

Order 1. =Polygonaceæ.= The majority are herbaceous plants with round, often jointed stems, scattered leaves and _ocrea_, that is a membranous, tubular, ligular or stipular structure _inside_ the base of the leaf, which clasps the stem and axillary bud; the edges of the lamina are rolled backwards in the bud. The flowers are regular, small, generally ☿, slightly perigynous, with inconspicuous, simple, green or white perianth of 5–6 free segments; stamens 5–9 (Fig. 354) sometimes arranged in two series; gynœceum 2–3 carpels, ovary _unilocular_ with _one basal_, _straight_ (orthotropous) _ovule_, 2–3 _free styles_. The fruit is a 2–3-angular nut; the embryo, with mealy endosperm, is straight or curved (Fig. 355 _H_), often unsymmetrical.--~The inflorescences are compound, and generally branch from the axils of the bracteoles, so that the last partial-inflorescences become coiled, uniparous scorpioid cymes; in _Polygonum_ the two bracteoles unite into a membranous tube; in _Rheum_ and _Rumex_ there is only one bracteole.~

_Rheum_ (Rhubarb, Fig. 354 _A_) has a 6-leaved, _petaloid_ perianth (Pn 3 + 3) and 9 stamens (A 3^2 + 3). The _3-winged_ nut is _not_ enclosed by the perianth.

_Rumex_ (Dock, Fig. 354 _B_) has 6 stamens (A 3^2 + 0); the perianth is 6-leaved (Pr 3 + 3), green or red, and the triangular nut is enveloped by the 3 interior perianth-leaves, which point upwards and continue to grow after flowering. These perianth-leaves often have warts on their outer surface. ~The following are monœcious: _R. acetosa_ and _R. acetosella_.~

_Polygonum_ (Knot-grass, Figs. 354 _C_, _D_; 355). The _petaloid_ perianth is most frequently 5-merous (2/5 spiral); 5–8 stamens. The nut is triangular (Fig. 354 _C_, 355), or lenticular (Fig. 354 _D_). ~There are two whorls of stamens, the external with introrse, and the internal with extrorse anthers. The gynœceum is often bicarpellate (Fig. 354 _D_).~

The flowers may be considered as constructed upon the
monocotyledonous type. _Pterostegia_ has a perfectly
monocotyledonous flower with 5 trimerous whorls. _Rheum_
likewise, but here the external staminal whorl is doubled (Fig.
254 _A_). _Oxyria_ has a dimerous _Rheum_-flower (4-leaved
perianth, 6 stamens, 2 stigmas). _Rumex_ has a _Rheum_-flower
with the suppression of the internal whorl of stamens (Fig.
354 _B_); _Emex_ is a dimerous _Rumex_. _Polygonum_, to which
_Coccoloba_, _Muehlenbeckia_ and others are related, differs
from _Rheum_ chiefly in having one of the leaves, which in the
latter takes part in the formation of the perianth, developed
in this case into a bracteole (so that the perianth is reduced
to five members), and several or all the stamens in the inner
whorl become suppressed.--The perianth in _Coccoloba_ and
_Muehlenbeckia_ is more or less perigynous and becomes fleshy,
enclosing the fruit. _Muehlenbeckia platyclada_ has flat branches
with rudimentary leaves; sometimes branches with normal,
arrow-shaped leaves are found. _Atraphaxis._

POLLINATION. _Rumex_ is wind-pollinated, the stigmas are
therefore large and brush-like (indicated in Fig. 354 _B_).
_Rheum_ and _Polygonum_ are insect-pollinated and have therefore
capitate stigmas, etc.; honey-glands are situated at the base
of the stamens (_d_, in Fig. 354 _C_, and _n_ in Fig. 356); a
few small-flowered _Polygonum_ species are self-pollinated;
Buckwheat (_P. fagopyrum_) is dimorphic and has long-styled and
short-styled flowers (Fig. 356). _Pol. bistorta_ is protandrous
and homostyled.

About 750 species, most of which are found in the temperate
regions of the Northern Hemisphere, some reaching as far as the
snow line or into the Arctic regions (_Oxyria_, _Kœnigia_).
Trees and shrubs are found in the Tropics: _Coccoloba_,
_Triplaris_. _Rheum_ is Central Asiatic.--The thick rhizomes of
_R. officinale_ (_Rhubarb_) are _officinal_. The rhizomes of the
ordinarily cultivated species, _R. undulatum_ and _rhaponticum_,
are used in veterinary medicine. The following are cultivated as
culinary plants for the sake of their leaves:--_Rumex acetosa_
(Sorrel), _R. patientia_, _R. scutatus_, and _Rheum undulatum_
(petioles). Several species of _Polygonum_ (_P. hydropiper_ and
others) have a sharp, pungent taste. “Buckwheat” is the mealy
fruit of _Polygonum fagopyrum_ (Central Asia) and is of value as
a farinaceous food. _P. cuspidatum_ (_P. sieboldi_, Japan) is an
ornamental plant.--_Calligonum_ in sandy and stony deserts.

Order 2. =Piperaceæ (Peppers).= Shrubs or herbs, often with nodose, jointed stem; leaves simple, entire, often with curved veins; stipules wanting (_Peperomia_) or intrapetiolar and cap-like, often enclosing the terminal buds (_Piper_). The flowers in the group _Pipereæ_ (_Piper_, Fig. 357, and _Peperomia_) are borne in spikes with fleshy axes (_club-like_), seldom in racemes, the outer ones are crowded and are ☿ or unisexual, always small, _naked_ and without bracteoles; ~generally stamens 3 + 3, and gynœceum 3, but the number of the stamens may be reduced by suppression to 2, and the carpels to 1~. The flowers are situated in the axils of the small, generally shield-like floral-leaves. The ovary is always _unilocular_ and has _one upright, orthotropous_ ovule. Fruit a berry or drupe. Both endosperm and _perisperm_ are present, the latter being especially well developed (Fig. 359).

_Piper_; generally shrubs with scattered leaves, and terminal inflorescences which are crowded to one side by the development of the highest lateral bud, so that they are situated opposite the leaves (Fig. 357). Many species have stems with an abnormal anatomical structure.--_Peperomia_; chiefly succulent herbs, often epiphytes, with opposite or verticillate leaves having aqueous tissue on the upper side.

The group _Saurureæ_ (considered by some as an order, and
perhaps representing a more original type) has 3–4 carpels
with many ovules. _Lactoris_ stands the highest with regular
3-merous perianth, 3 + 3 stamens and 3 carpels, which are
united at the base. Fruit a capsule with several seeds. (It
has one species from the island of Juan Fernandez, and is also
placed in an order of its own, Lactoridaceæ, allied to the
Magnoliaceæ, through _Drimys_).--_Saururus_ has naked flowers;
most frequently 6 stamens, and 4 carpels, free or united at
the base, each with 2-4 orthotropous ovules. Fruit, small
berries.--_Houttuynia_; stamens situated a little upward on the
ovaries; placentation parietal; capsule many-seeded.

About 1,000 species; entirely tropical, especially from
South America and East India. They are found chiefly among
the underwood in damp, shady places; some, which are fleshy
(_Peperomia_), live as epiphytes on trees; a few climb by
roots.--USES. Several Piperaceæ are used medicinally and
for spices on account of their pungent properties and the
essential oils found in nearly all parts of the plant. The
following are _officinal_: “Black-pepper” (the unripe, dried
fruits) and “White-pepper” (the seeds of the ripe fruits) of
_Piper nigrum_ (climbing shrub, East Indian); “Cubeb” berries
of _P. cubeba_ (climbing shrub, Java). “Long-pepper” is the
unripe inflorescence of _P. longum_, East India. The leaves of
_P. angustifolia_ (Matico) are officinal. The leaves of the
Betelpepper (East India) are used together with the nuts of
the Areca-palm to form the well-known East Indian intoxicating
compound “Betel.” A good many others are also used.

Order 3. =Chloranthaceæ.= (_Chloranthus_, _Hedyosmum_) have
opposite leaves, with stipules more or less united at the base,
and inferior “drupes.” Ovules pendulous. Only endosperm. About
33 species, Tropical.

Family 7. =Curvembryæ.=

The plants in this family have a _curved ovule_, and most frequently a _kidney-shaped seed_ (generally provided with fine, cuticular, projecting warts, Fig. 362 _B_), with a _curved, peripheral embryo enclosing the endosperm which is most frequently floury_ (Figs. 362 _C_, 365 _H_; for exceptions, see Fig. 366); the seeds in all cases are borne on a _centrally-placed_, and in most cases _free_, placenta (they are “basal” when there is only 1 ovule in the ovary, Fig. 364). The flower is regular, hypogynous or perigynous (Fig. 364) (only rarely epigynous) and usually 5-_merous_. The flower which is most complete has 5 whorls (S5, P5, A5+5, G2-3–5), as in some genera of the Caryophyllaceæ (Figs. 360, 361); but from this type it becomes reduced, the petals and stamens being suppressed, so that finally 5 perianth-leaves, 5 stamens (opposite the perianth-leaves), and 2 carpels (Fig. 361 _F_) only are present; for example, in certain genera of the _Caryophyllaceæ_, in the _Chenopodiaceæ_, _Amarantaceæ_, and others. When the number of stamens is increased to more than 5 in the whorl, it is always possible to show that some of the stamens have been divided. The number of the carpels and ovules also becomes reduced; in the highest there is a central placenta, not free in its early stages, with a large number of ovules; in those which are most reduced there is only a single ovule, which is placed centrally at the base of the ovary [Fig. 364]. Somewhat corresponding changes are found in the fruit, which is a many-seeded _capsule_ in those which have many ovules, but a one-seeded _nut_ where there is one ovule. In the most reduced forms the flowers are generally unisexual.--Similar features are also present in the vegetative parts. Almost all the species are herbaceous, the leaves are simple and most frequently without stipules. ~The structure of the stem, especially in Chenopodiaceæ, Amarantaceæ, Nyctaginiaceæ and others, often differs from that of the ordinary Dicotyledon. In the woody portion of the stem and root several rings are sometimes formed which resemble annual rings but which are formed by new cambium-rings arising outside the old ones which then cease to divide.~

Order 1. =Caryophyllaceæ.= Herbaceous plants, with round, nodose stem; leaves _opposite_, slightly amplexicaul, simple, with sessile, undivided, entire lamina; stipules nearly always absent; the inflorescences are _dichasia_ passing over into unipared scorpioid cymes. The flowers are regular, ☿ or unisexual, hypogynous or perigynous, 5-(or 4-) merous with 2–3–4–5 carpels; calyx persistent; corolla polypetalous. The ovary is unilocular (or originally, and sometimes also in the later stages, plurilocular below, _e.g._ _Viscaria_), with _free styles_ and 1–several curved ovules on a _central_, free placenta. The fruit is a nut or a capsule opening apically with long or short valves (teeth, Fig. 362), equal to or double the carpels. For the seeds refer to the family. ~In _Dianthus_ the embryo is straight.~

The flowers which are most complete have _Sn_, _Pn_, _An_ + _n_
(obdiplostemonous), _Gn_ where _n_ = 5 (Figs. 360, 361 _A_) or
4 (Fig. 361 _B_); the carpels may be placed opposite to the
sepals (Fig. 360) or opposite to the petals (Fig. 361 _A_, _B_).
Without any change taking place in the position of the other
whorls, the carpels are next found reduced to 2–3–4 (see the
genera); their number may easily be recognised by that of the
styles. This is the construction in the majority of the genera
in the two first groups. _Stellaria media_ differs considerably.
It may have (_a_) the flower as described above, with _G3_;
(_b_), the corolla only absent, or (_c_) only the petal-stamens
(A5 + 0, Fig. 361 _C_), or (_d_) all these as well as some of
the sepal-stamens. The same applies to _Sagina_, _Alsine_,
_Cerastium_, and others, and, finally, a series of genera are
formed, with certain conditions of reduction which have become
constant, and by a gradual series of steps lead to the most
reduced form, which has only 5 sepals and 5 (or even as far as
only 1) sepal-stamens (Fig. 361 _D_, _E_, _F_).--The PETALS in
the _Alsineæ_ are often deeply bifid. The sepal-stamens are most
frequently the longest, and bear nectaries at the base (Fig. 363
_st_). In the most complete forms the ovary has partition-walls
in the lower portion (Fig. 360); these do not, however, reach
to the top, and generally soon disappear. The ovules, when
numerous, are situated on the placenta in as many double rows as
there are carpels. In the number of ovules a reduction from many
to 1 takes place (Fig. 361). A comparison proves that the “free,
centrally placed” placenta is formed by the ventral portion of
the carpels. The single basal ovule in _Herniaria_ (Fig. 364),
_Scleranthus_, and others, is also borne on the carpels.

The vegetative _branching_ is characteristic. One of the leaves
in a pair is formed before the other, and has a more vigorous
axillary bud; these stronger leaves stand in a ¼-spiral, the
fifth above the first one, and the branches are consequently
arranged in the same manner. In the inflorescence, however, it
is the upper or second bracteole (β) whose axillary bud (_w_ in
Fig. 361) is most advanced. The bud of the first bracteole (α)
becomes sometimes entirely suppressed, or in some this bracteole
itself is suppressed.

The most original type appears to be represented by the Alsineæ.
From this form on one side the Sileneæ, adapted in a higher
degree for insect-pollination, are developed, and on the other
side the Paronychieæ, with various reductions.

=1.= ALSINEÆ, STITCHWORT GROUP. Sepals free, and connected with them stellately expanded, slightly unguiculate (white or inodorous) petals; these, however, often become suppressed (Fig. 363). The fruit is a capsule.

=a.= As many carpels as sepals (4 or 5). _Cerastium_ (Chickweed). The petals are bifid. Capsule cylindrical, frequently _curved_ at the top, and opening by 10 teeth (Fig. 362).--~_Malachium_ differs only in the 5-toothed capsule with bifid teeth.~--_Spergula_ (Spurry). The petals are not bifid, capsule 5-valved; seeds winged. The leaves are linear, and appear as if placed in large numbers in a whorl, a branch being situated in the axil of each with leaves placed very close together at its base; _stipules membranous_.--~Sagina has Sn, Pn, An + n, or An, Gn, where n = 4 or 5. The corolla is often wanting.~

=b.= 3 (rarely 2) carpels (Fig. 361 _C_). _Stellaria_ (Stitchwort) has deeply cleft petals. The number of stamens varies (see above).--_Arenaria_ has entire petals. ~(To this group belong _Alsine_, _Moehringia_, _Halianthus_, or _Honckenya_ (Fig. 363), which differ from each other, especially in the form of the seed and number of the capsular valves.) _Spergularia_ has membranous stipules, as in _Spergula_.--_Holosteum._~

=2.= PARONYCHIEÆ (Figs. 361 _D_, _E_, _F_; 364). Small, greenish plants. The leaves, in the majority, are opposite, with _membranous stipules_. The flowers are most frequently arranged in small _dichasia_; they are small and insignificant, perigynous (Fig. 364) or hypogynous. The corolla is in most cases wanting, and when present is very small; in general the calyx-stamens are developed, but the corolla-stamens may be represented by small scales (Fig. 364). Ovary most frequently with 1 ovule. Fruit, a _nut_, rarely a capsule; it is enclosed by the strongly perigynous floral axis (torus).

_Scleranthus_ (Knapwell) is perigynous with bell-shaped torus; no corolla; corolla-stamens are wanting or rudimentary; some calyx-stamens may also be absent.--_Corrigiola_ (Fig. 361 _D_); _Illecebrum_; _Paronychia_ (Fig. 361 _E_); _Herniaria_ (Figs. 361 _F_, 364).

=3.= SILENEÆ, PINK OR CARNATION GROUP. This has a _gamosepalous_ calyx and unguiculate, white or red, petals, with _outgrowths_ (_ligule_, _corona_, _paracorolla_) at the throat of the corolla. These structures are not found in the other groups, and are merely outgrowths at the junction of the limb and claw. The corolla, stamens and ovary are frequently raised above the calyx, upon a lengthened internode (_gynophore_). The flower has S5, P5, A5 + 5; fruit a capsule with many seeds.

=a.= 5-(rarely 3–4) carpellate ovary.--_Lychnis_ (Campion, Fig. 360). The corolla is longer than the calyx; corona present. The capsule is 10- or 5-toothed, completely 1-chambered or 5-chambered at the base,--the genus has been divided accordingly into several genera: _Melandrium_, _Lychnis_, _Viscaria_. ~Some species are unisexual by the abortion of stamens or carpels (_L. vespertina_, _diurna_).~ _Agrostemma_ (_A. githago_, Corn-cockle, Fig. 361 _A_) has a long-toothed calyx, the teeth exceeding the corolla; corona absent; 5-toothed capsule.

=b.= Tricarpellate.--_Silene_ (Catch-fly). Six-toothed capsule; corona present in the majority.--~_Cucubalus_ has berry-like fruits which finally become dry but do not dehisce.~

=c.= Bicarpellate (2 styles, 4-toothed capsule).--_Dianthus_ (Pink); at the base of the calyx 1–several pairs of floral-leaves are situated; corona absent. The _straight embryo_ is a peculiar exception.--_Gypsophila_ has a campanulate, open calyx, 5-nerved, membranous between the nerves; corona absent; the flowers are generally small and numerous, in a large, paniculate dichasia.--_Saponaria_ (Soapwort) has corona.

POLLINATION. _Alsineæ_ has ordinary nectaries at the base of
the calyx-stamens (Fig. 336): they are frequently protandrous
but may often, in the absence of cross-pollination (in the
less conspicuous species) pollinate themselves. Their open
flowers are accessible to many kinds of insects (particularly
flies and bees). _Gynodiœcious_ flowers are found in several
species, and the ☿-flowers are then generally more conspicuous
than the ♀-flowers. That the ♀-flowers have descended from
☿-flowers is seen by the large staminodes found in them (Fig.
363). _Arenaria peploides_ is diœcious (Fig. 363). The _Sileneæ_
are as a rule adapted for pollination by insects with long
probosces--especially butterflies,--and they are frequently
protandrous, so that at first the calyx-stamens open, later
on the corolla-stamens, then the stigmas expand. The honey is
secreted by a ring-like nectary round the base of the ovary or
by nectaries at the base of the stamens. Some only blossom and
emit scent at night or in the evening (_Lychnis vespertina_,
_Silene nutans_, _Saponaria officinalis_) and, like other
night-flowers, are of a white or pale colour.

DISTRIBUTION. 1,100 species, especially in temperate climates,
fewer in the colder zone, less still in the Tropics. The
Paronychieæ are especially found in dry, sandy fields.

USES. “Soap-root” (with _Saponin_, forming a lather in water)
from _Saponaria officinalis_ was formerly officinal, and
_Gypsophila struthium_. The seeds of _Agrostemma githago_ are
said to be poisonous.--The following are ornamental plants:
species of Pinks (_D. caryophyllus_, garden Pink, often
with double flowers; _D. barbatus_, _plumarius_, _etc._).
_Lychnis_, _Gypsophila_, _Silene_, _Cerastium_ (_C. tomentosum_
as edging for borders), _Saponaria officinalis_ (often
coronate).--_Spergula arvensis_ is sometimes cultivated.

Order 2. =Amarantaceæ.= The flowers are essentially the same as
in the _Chenopodiaceæ_ and the extremely reduced Caryophyllaceæ
(Fig. 361 _F_); they are regular, hypogynous, generally ☿,
have 5 free (rarely slightly united) perianth-leaves; in front
of these 5 stamens, which _are often united_ at their base
into a shorter or longer tube and have stipule-like teeth
between them (the division _Gomphreneæ_ has 2-locular anthers,
each of which opens longitudinally); and a 2–3 carpellate
gynœceum with one loculus and most frequently one, more rarely
several ovules; the fruit is a nut, more rarely (in _Celosia_,
_Amarantus_, _Gomphrena_) a capsule, dehiscing irregularly,
or like a pyxidium. The characters which especially separate
them from the allied orders are found in the perianth. The
perianth-leaves are not green and herbaceous, but _membranous,
dry, and often coloured_; they are frequently produced into a
bristle or awn; they have also both subtending floral-leaves
and _2 large bracteoles similar to the perianth_; all these dry
leaves persist without alteration after the withering of the
flower.--The flowers are without scent. They are arranged in
spike- or capitulum-like inflorescences; sometimes placed singly,
sometimes aggregated in the panicle-like inflorescences; in
others, on the contrary, in dichasia. The majority are herbs,
some are shrubs. The leaves are scattered, or opposite, but
always simple and without stipules; some are smooth, others
hairy.

450 species; especially in the Tropics, principally S. Am. and
E. Ind.: few are found outside these countries.--Only a few
are used; some, chiefly E. Indian species, are cultivated as
ornamental plants: _Amaranthus_ (Fox-tail); _Gomphrena globosa_;
_Celosia cristata_ (Cock’s-comb) remarkable for its fasciated
inflorescence; _Alternanthera_. Some are employed as culinary
plants in the Tropics, and in a few of the E. Indian species the
seeds are farinaceous, and used for food.