Chapter II: ACROGYNÆ. The apex of the stem or of certain branches is adapted (4)

Some of the numerous _Juncus_-species (_e.g. J. effusus_,
_glaucus_, _conglomeratus_, etc.), have false, lateral
inflorescences, the axis of the inflorescence being pushed
to one side by its subtending leaf, which apparently forms
a direct continuation of the stem, and resembles it both
in external and internal structure. The foliage-leaves of
this genus were formerly described as “unfertile stems,”
because they are cylindrical, erect, and resemble stems, and
consequently the stem was said to be “leafless”: _J. effusus_,
_glaucus_, _conglomeratus_. Stellate parenchynatous cells are
found in the pith of these stems and in the leaves. Other
species have distinct terminal inflorescences and grooved
leaves; _J. bufonius_ (Toad-rush), _compressus_, and others.
The _inflorescences_ most often present the peculiarity of
having the lateral axes protruding above the main axis.
Their composition is as follows:--The flowers have either no
bracteoles, and the inflorescences are then capitulate; or
they have 1–several bracteoles. Each branch has then, first,
a 2-keeled fore-leaf placed posteriorly (“basal-leaf”), and
succeeding this are generally several leaves borne alternately
and in the same plane as the basal-leaf, the two uppermost
(the “spathe-leaves”) being always barren; those which lie
between the basal-leaves and the spathe-leaves are termed
“intermediate-leaves.” If only branches occur in the axils
of the basal-leaves, then the succeeding branches are always
borne on the posterior side of the axis, and form a fan[27];
if the basal-leaf is barren, and if there is only one fertile
intermediate-leaf, then the lateral axes are always on the upper
side, and a sickle[27]-like inflorescence occurs; if there are 2
fertile intermediate-leaves, then a dichasium is formed, and in
the case of there being several, then a raceme, or spike.

_Juncaceæ_ are, by several authors, classed among the
Liliifloræ, but there are so many morphological and partly
anatomical features agreeing with the two following orders, that
they may, no doubt, most properly be regarded as the starting
point of these, especially of the _Cyperaceæ_, which they
resemble in the type of flowers, the inflorescence, the type of
mechanical system, and the stomata.

POLLINATION by means of the wind. Cross-pollination is
often established by protogyny. _J. bufonius_ has partly
triandrous and cleistogamic, partly hexandrous, open
flowers.--DISTRIBUTION. The 200 species are spread over the
entire globe, but especially in cold and temperate countries;
they are seldom found in the Tropics.--USES. Very slight;
plaiting, for instance.

Order 2. =Cyperaceæ.= The majority are _perennial_ (seldom annual) _herbs_ living in damp situations, with a sympodial rhizome and grass-like appearance. The stems are seldom hollow, or have swollen nodes, but generally _triangular_, with the upper internode just below the inflorescence generally very long. The leaves are often arranged in 3 _rows_, the leaf-sheath is _closed_ (very seldom split), and the ligule is absent or insignificant. The flowers are arranged in _spikes_ (_spikelets_) which may be united into other forms of inflorescences (chiefly spikes or racemes). The flowers are supported by a bract, but have _no bracteoles_. In some genera the perianth is distinctly represented by six bristles corresponding to six leaves (Figs. 284 _A_, 286 _A_); in others it is represented by an indefinite number of hairs (Fig. 284 _B_), and very frequently it is altogether wanting. _The inner whorl of stamens is absent_, and the flower has therefore 3 stamens (rarely more or less than 3), the anthers _are attached by their bases to the filament_ (innate) and are not bifid (Figs. 286). Gynœceum simple, formed of 3 or 2 carpels; 1 style, which is divided at the extremity, as in the Juncaceæ, into 3 or 2 arms; the single loculus of the ovary contains one basal, erect, anatropous ovule; the stigmas are not feather-like. _Fruit a nut_, whose seed is generally not united with the pericarp. The embryo is small, and lies at the _base of the seed in the central line_, surrounded on the inner side by the endosperm (Fig. 286 _B_). On germination the cotyledon _does not remain_ in the seed.

A regular perianth, with 6 scale-like perianth-leaves in 2
whorls, is found in _Oreobolus_. In _Scirpus littoralis_ the
perianth-leaves are spreading at the apex, and divided pinnately.

The branching of the inflorescence is often the same as in the
Juncaceæ, and supports the theory that these two orders are
related. In _Rhynchospora_ and others, the “spikelets” are
really only “spike-like” and to some extent compound.

=A.= SCIRPEÆ. HERMAPHRODITE FLOWERS.

1. Spikelets cylindrical, the bracts arranged spirally (in many rows). The lower ones are often barren, each of the others supports a flower.--_Scirpus_ (Club-rush). The spikelets are many-flowered; the perianth is bristle-like or absent, and does not continue to grow during the ripening of the fruit (Fig. 286 _A_). Closely allied to this is _Heleocharis_, with terminal spikes.--_Eriophorum_ (Cotton-grass) differs chiefly in having the perianth-hairs prolonged, and forming a bunch of white, woolly hairs (Fig. 284 _B_).

_Cladium_ and _Rhynchospora_ (Beak-rush) differs especially in
the _few_-flowered, compound spikelets which are collected into
small bunches; the latter has received its name from the fact
that the lowermost portion of the style remains attached to the
fruit as a beak.

2. Spikelets compressed, the bracts arranged only in _two rows_; the other characters as in the first-mentioned. _Cyperus_ (spikelets many-flowered); _Schœnus_ (Bog-rush); spikelets few-flowered; _S. nigricans_ has an open sheath.

=B.= CARICEÆ. UNISEXUAL FLOWERS.

In the ♂-flowers there is no trace of a carpel, and in the ♀ no trace of a stamen. Floral-leaves in many rows. In some (_Scleria_, certain _Carex_-species), ♂-and ♀-flowers are borne in the same spikelet, the latter at the base or the reverse; in the majority each spikelet is unisexual.

_Carex_ (Fig. 285) has _naked_, most frequently monœcious flowers. The ♂-_spikes_, which are generally placed at the summit of the whole compound inflorescence, are _not compound_; in the axil of each floral-leaf (bract) _a flower is borne, consisting only_ of a short axis with three stamens (Fig. 285 _A_). The ♀-_spikes are compound_; in the axil of each floral-leaf is borne a very small branch (Fig. 285 _D_, _a_) which _bears only one leaf_, namely, a _2-keeled fore-leaf_ (_utriculus_, _utr._ in the figures) which is turned posteriorly (as the fore-leaves of the other Monocotyledons), and being obliquely sheath-like, envelopes the branch (in the same manner as the sheath of the vegetative leaves), and forms a pitcher-like body. In the axil of _this_ leaf the ♀-flower is situated as a branch of the 3rd order, bearing only the 2–3 carpels, which are united into one gynœceum. The style protrudes through the mouth of the utriculus. ~The axis of the 2nd order (_a_ in Fig. 285 _D_) may sometimes elongate as a bristle-like projection (normally in _Uncinia_, in which it ends as a hook, hence the name); this projection is in most cases barren, but it sometimes bears 1–several bracts which support male-flowers; this is normal in _Elyna_ (or _Kobresia_) and _Schœnoxiphium_; the axis (_a_ in 285 _E_) bears at its base a female-flower supported by the utriculus, and above it a male-flower supported by its bract.~

POLLINATION by means of the wind. Protogynous. Sometimes
self-pollinated. The order embraces nearly 3,000 species, found
all over the world. _Carex_ and _Scirpus_ are most numerous in
cold and temperate climates, and become less numerous towards
the equator. The reverse is the case with _Cyperus_ and other
tropical genera. They generally confine themselves to sour,
swampy districts; some, on the other hand, are characteristic
of sand-dunes, such as Sand-star (_Carex arenaria_). There are
about 70 native species of _Carex_.

USES. In spite of their large number, the Cyperaceæ are of
no importance as fodder-grasses, as they are dry and contain
a large amount of silica; hence the edges of many of the
triangular stems or leaves are exceedingly sharp and cutting.
_Cyperus esculentus_ has tuberous rhizomes, which contain a
large amount of fatty oil and are edible (earth-almonds); it
has its home in the countries of the Mediterranean, where it is
cultivated.

_Cyperus papyrus_ (W. Asia, Egypt, Sicily) attains a height of
several metres, and has stems of the thickness of an arm which
were used by the ancient Egyptians for making paper (papyrus).
Some serve for plaiting, mats, etc. (_Scirpus lacustris_, etc.).
_Isolepis_ is an ornamental plant.

Order 3. =Gramineæ= (=Grasses=). The stems are cylindrical, generally _hollow_ with _swollen nodes_, that is, a swelling is found at the base of each leaf which apparently belongs to the stem, but in reality it is the swollen base of the leaf. The leaves are _exactly alternate_; the sheath is _split_ (excep. _Bromus_-species, _Poa pratensis_, _P. trivialis_, _Melica_, _Dactylis_, etc., in which the sheath is not split), and the edges overlap alternately, the right over the left, and _vice versâ_; the _ligule_ is nearly always well developed. In general, the flowers are hermaphrodite; they are borne in _spikelets_ with _alternate floral-leaves_, and the spikelets themselves are borne in either _spikes_ or _panicles_. The two (seldom more) _lowest floral-leaves_ in each spikelet (Fig. 289 _øY_, _nY_) are _barren_ (as the covering-leaves in many umbels and capitula); these are termed the _glumes_. The succeeding floral-leaves, each of which supports one flower as its bract, are called the _outer pales_ (_nI_); these sometimes each bear an “awn” (a bristle-like body which projects in the median line either from the apex or the back); sometimes the upper ones are barren. Each flower has a _bracteole_, which is placed on the inside opposite the main axis; it is thin, _binerved_ or _two-keeled_, and never has an awn; it is known as the _inner pale_ (_øI_). Immediately succeeding the bracteole are: (_a_) some _small, delicate scales_ (_lodicules_, Figs. 287 _D_, 288 _C_, 290 _L_); (_b_) _three stamens_ with anthers _versatile_, so as to be easily moved, and usually notched at each end (Fig. 287 _C_); and (_c_) a simple gynœceum formed of _one carpel_ with _two styles_ having generally _spirally-branched stigmas_ (Figs. 287 _D_, 288 _C_). The ovary is _unilocular_, and contains one ascending or pendulous, anatropous ovule. _Fruit a nut_, whose seed is always _firmly united with the thin pericarp_ (“caryopsis”). The embryo is larger than in the Cyperaceæ and is placed at the base of the seed, but on the _outer convex surface_ of the pericarp (Figs. 287 _I_, 288 288 _D_, 291), _outside the endosperm_; plumule large with several leaf-primordia. On germination the cotyledon remains in the seed.

The majority of Grasses are annual or perennial herbs; tree-like forms being only found in the Tropics, for example, the Bamboos; they branch (in tufts), especially from the axils of the basal-leaves, while those which are borne higher on the stem are separated by longer internodes and have no vegetative branches in their axils, though a few forms, like _Bambusa_ and _Calamagrostis lanceolata_, produce branches in these axils.

Only a few Grasses have a _solid stem_, such as Maize,
Sugar-cane, and _Andropogon_. The _blade_ is flat in the
meadow-grasses, but the Grasses which live on dry places
(“prairie-grass”) exposed to the sun, often have the blade
tightly rolled up and almost filiform or bristle-like, with
anomalous anatomical structure. A _closed_ tubular _sheath_ is
found in _Melica uniflora_, _Bromus_-species, _Poa pratensis_
and _trivialis_, _Briza_ and some _Glyceria_-species. The
sheath is developed for the purpose of supporting the young
internodes while their growth is proceeding at the base. The
“nodes” (the swollen joints which are seen on stems of Grasses)
are not really part of the stem but are formed by the base of
the leaf-sheath. They play a part in assisting the haulms
to regain a vertical position when laid prostrate by wind
or rain. The _awn_ on the pale is homologous with the blade
of the Grass-leaf, and the pale itself is the sheath. The
arrangement of the leaves in the _spikelet_ is similar to that
in _Cyperus_ and other Cyperaceæ, their floral-leaves being
borne in several rows in _Streptochæta_. More than two barren
“glumes” are found in _Streptochæta_, several Phalarideæ and
others. The spikelets, too, are again arranged in two rows in
the axils of suppressed floral-leaves. The inflorescence becomes
a “compound spike” (ear) when the spikelets are sessile. In the
majority of instances the spikelets are borne on long stalks;
when these branch, then the secondary branches, and similarly
all branches of higher order, are placed so far down upon the
mother-axis that they all appear to be of equal value and to
arise in a semicircle from the mother-axis itself, though in
reality they arise from each other (_Panicle_, Fig. 288 _A_).
Sometimes the main axis and branches of different orders unite
together as in _Alopecurus_, _Phleum_, and some other Grasses,
and hence the single (short-stalked) spikelets appear to arise
singly and spirally, or without any definite order, directly
from the main axis, with the production of a _cylindrical_
inflorescence bearing “spikes” _on all sides_, that is, a
“_spike-like panicle_.”--Many inflorescences are somewhat
dorsiventral. The _flower_ is rarely unisexual (_Zea mais_) or
barren. Considerable difficulty is experienced in reducing the
Grass-flower to the ordinary 3-merous Monocotyledonous type.
Some authorities consider the _lodicules_, which are present
in all Grasses but absent in the Cyperaceæ, to be homologous
with a perianth. According to a more recent theory they are
bracteoles, and hence the Gramineæ, like many of the Juncaceæ,
have 2–3 bracteoles placed in two rows in the median plane. If
this theory be correct, the _flower is naked_. The lodicules
expand quickly and cause the opening of the flower (_i.e._ the
two pales become separated from each other). Generally only 3
_stamens_ belonging to the outer whorl are present (Fig. 290),
as in _Iris_ (Fig. 279), certain Juncaceæ and Cyperaceæ (Fig.
284), but in some, such as the Rice and certain species of
Bamboos, all 6 are found. _Pariana_ has more than 6. Only 1 of
the _carpels_ is present, namely, the anterior (of those in Fig.
284), so that the ventral suture and the place of attachment
of the ovule are situated at the back of the ovary. The number
of styles does not correspond with the number of carpels, and
the styles may therefore be supposed to arise from the edges
of the leaf to the right and left--a position which is not
without analogy. In addition, a stylar projection is sometimes
found on the anterior side and in the median line (_e.g._ in
_Phragmites_), and the solitary style in _Nardus_ has exactly
this position; a similar arrangement is found in some species of
_Bambusa_ which have only one style; other species of _Bambusa_
have three styles. A tripartite style is found in _Pharus_.

[The Grass-flower may be reduced to the ordinary
Monocotyledonous type thus:--The outer pale is the bract of the
flower since it bears in its axil the floral shoot; the inner
pale occupies the customary position of the bracteole. The fact
that it is binerved can be explained by its having been pressed
against the main-axis during development. Similar binerved
bracteoles are found in _Iris_ (Fig. 279). These bracteoles in
both Grass and Iris arise from single primordia, and are not
produced by the coalescence of two leaves. The lodicules are the
only parts of the perianth remaining, the outer whorl having
been suppressed, and also the posterior leaf of the inner whorl;
a posterior lodicule, however, is found in the Rice and some
species of Bamboo. The outer whorl of stamens is usually absent,
though this again is present in the Rice and Bamboo. The three
carpels are reduced to one with two or sometimes three stigmas.]

THE FLOWERING. In the panicles the flowers open in basipetal
order; the flowers in the spikes situated somewhat above the
middle, commence to open first, and the flowering proceeds
upwards and downwards. A few Grass-flowers never open
(cleistogamic); _Leersia oryzoides_, _Stipa_-species, and _e.g._
Wheat and Rye in cold damp weather; some open their pales so
wide that the anthers and stigmas may protrude at the top; most
frequently the lodicules expand and force the pales suddenly
and widely apart. The filaments elongate considerably, so that
the anthers are pendulous and the stigmas unfold. In some
Grasses _e.g._ Wheat, the blooming of each flower only lasts
a short time. POLLINATION is generally effected by the wind.
The _Rye_ separates the pales very widely in the morning, and
allows the anthers and stigmas to appear; it is almost entirely
sterile when self-pollinated. The _Wheat_ flowers at any time
of the day, each flower lasting only a quarter of an hour. The
pales open suddenly, but only half way, and the anthers scatter
one-third of the pollen in their own flower and two-thirds
outside. Self-pollination is effectual, but crossing gives
better results. In _Hordeum vulgare_ (all flowers ☿) the flowers
of the 4 outer rows behave as in the Wheat, but those in the
two central rows always remain closed. The ☿-flowers in the
two central rows of _H. distichum_ remain closed and fertilise
themselves; they open exceptionally, and may be pollinated
by the ♂-flowers in the 4 lateral rows. _H. hexastichum_ is
cleistogamic. _Oats_ pollinate themselves.

_The ripe Grass-fruit_, in some species of Bamboo, is a berry;
in some other Grasses a nut with _loosely_ lying seed, in some
even a capsule, but otherwise a “caryopsis.” In some instances
it is loosely enveloped by the pales (Oat), in others firmly
attached to these (Barley), and finally, in others, “naked,”
_i.e._ it is entirely free from the pales (Wheat and Rye).
On the ventral side there is a groove (Fig. 288 _E_); on the
anterior side (dorsal suture), which is turned towards the
inner pale, it is convex, and at the base on this side, inside
the testa, lies the embryo (Fig. 288 _D_). The apex of the
fruit is often hairy (Fig. 293). The _skin_ (Fig. 291, _a_) is
formed by the pericarp and testa, and in some cases (Barley)
the pales also form the outer portion. The endosperm (_b_) is
large, and formed of parenchymatous, starch-containing cells:
aleurone (proteid) grains may also be found among them. When
the starch-grains and the aleurone-grains adhere together
the endosperm becomes “horny,” but is “floury” when the
starch-grains lie loosely with air between them. In the most
external region, just beneath the skin, 1–several layers of
nearly cubical cells (filled principally with aleurone-grains
and fat) are found, the _aleurone_-layer (Fig. 292). The embryo
(Fig. 291 _c-d_) contains large quantities of fatty oil;
the large shield-like structure, attached to the embryo and
turned inwards towards the endosperm (_c_), is the cotyledon
(scutellum); it remains enclosed in the seed during germination,
and dissolves the endosperm by means of the peculiar epithelial
cells developed on the dorsal surface. The radicle, on
germination, is obliged to perforate a mass of cells derived
from the suspensor and which form the “root-sheath” (coleorhiza,
Fig. 293) round its base. In addition to the tap-root, lateral
roots are frequently developed before germination; these quickly
break through, and later on are followed by others which appear
at the base of the leaf (Figs. 293, 294).

The DISTRIBUTION OF THE FRUIT is most frequently effected by the
wind. The spirally-twisted and hygroscopic awn which persists on
the fruits of some species (_Avena_, _Stipa_, etc.) assists in
their dissemination, and even helps to bury them in the ground.

The two preceding orders are more closely related to each other
than they are to the Gramineæ.

The generic differences are chiefly founded on the form of
the inflorescence, the number and sex of the flowers in the
spikelets, the shape and relative length of the pales, awns,
etc. In addition to these the structure of the fruit and
seed presents a great many differences; some have compound
starch-grains, while in others they are single; some have 1
layer of aleurone-cells, others have several (Fig. 292), etc.

=1.= BAMBUSEÆ. Tall Grasses with woody, very siliceous stems which bear many branches in the axils of the leaves. 6 stamens. _Bambusa_ (Bamboo).

=2.= ORYZEÆ. _Oryza sativa_ (Rice) is a herbaceous marsh-plant, with panicle and small, 1-flowered spikelets, with two small glumes and two large, boat-shaped, strongly siliceous pales. 6 stamens.--_Leersia._ _Lygeum. Pharus. Zizania aquatica._

=3.= MAYDEÆ. _Zea mais_ (Indian-corn, Maize); the spikelets are unisexual; the ♂-spikelets in a terminal panicle; the ♀-spikelets closely crowded and arranged in many rows in a thick, axillary spike, enclosed by large sheathing-leaves. The ♀-spikelets are 1-(2-) flowered; the ovary bears one, long, filamentous style, with bifid stigma.--_Euchlæna_; _Coix_.

=4.= ANDROPOGONEÆ. _Saccharum_ (Sugar-cane); the spikelets are exceptionally small, 1-flowered, and borne in pairs in many-flowered, long-haired panicles. Tall grasses with solid, sappy stem.--_Andropogon._

=5.= FESTUCEÆ. Grasses with panicle (or spike-like panicle) and 2–several-flowered spikelets. Glumes small, in each case shorter than the spikelet.--_Festuca_ (Fescue) and _Bromus_ (Brome, Fig. 288) have the awn placed at the _apex_ of the pale, or slightly below it. _Festuca_ has perennial species, with only a sparsely-branched panicle with branches solitary or in pairs, and round spikelets; the leaf-sheath is widely open. _Bromus_ has the branches borne in half whorls, and the leaf-sheath scarcely half open. _Brachypodium_ has very short-stalked spikelets in a raceme.--_Poa_ (Meadow-grass), _Briza_ (Quaking-grass) and _Glyceria_ have awnless spikelets; these in _Poa_ are ovoid, compressed, and with sharply-keeled glumes; in _Briza_ they are broad, cordate and drooping, with boat-shaped glumes; in _Glyceria_ round, long, many-flowered, linear or lanceolate; some species of _Glyceria_ have closed leaf-sheaths.--_Dactylis_ (Cock’s-foot) differs from all others in the somewhat crowded and unilateral (subsecund) spikelets, which are compressed and oblique (_i.e._ one side more convex than the other).--_Phragmites_ (_P. communis_, Reed); the lowermost flowers of the spikelet are ♂; its axis is covered with long, silky hairs; pales without awns, but acuminate. Perennial marsh-plants.--_Melica_; panicle small, sparsely-branched with round, awnless, few-flowered, usually drooping spikelets. The upper pales, with arrested flowers, are generally united into a club-like mass.--_Molinia_, _Eragrostis_, _Koeleria_, _Catabrosa_.--_Cynosurus_ (Dog’s-tail) has a small, spicate panicle with unilateral spikelets, some of which are fertile, some barren, each supported by a pectinate scale. _Arundo. Sesleria. Gynerium. Triodia._

=6.= AVENEÆ. Panicles with 2–many-flowered spikelets; at least one of the glumes is quite as long as the entire spikelet.--_Avena_ (Oat). The pale is boat-shaped, often bifid, and at about the middle of the back has a twisted, bent awn.--_Aira_ (Hair-grass) has a long-branched panicle with small, 2-flowered spikelets; the pale has a dentate apex and bears an awn on the posterior side close to the base.--_Weingærtneria._--_Holcus_ (Yorkshire-fog); a soft, hairy Grass with an open panicle, keeled glumes; 2 flowers in the spikelet, of which the lower one is ☿, the upper ♂; the pale which supports the ☿-flower has no awn, but that which supports the ♂-flower, on the contrary, is awned.

=7.= AGROSTIDEÆ. Panicles or spike-like panicles with 1-flowered spikelets. Generally 2 glumes and only 1 pale.--The following have PANICLES: _Milium_ with square panicle-branches and round spikelets; _Agrostis_ (Fiorin), with compressed, glabrous spikelets, whose glumes are longer than the pales. _Calamagrostis_ differs in having a chaplet of long hairs at the base of the pale.--_Stipa_ (Feather-grass) has a long, twisted awn.--The following have SPIKELIKE PANICLES: _Phleum_ (Cat’s-tail, Timothy-grass) has sharply pointed, entirely free glumes, which are much longer than the awnless pales. _Alopecurus_ (Fox-tail); glumes united below; pale with awn. _Ammophila_ (_Psamma_). _A. arundinacea_; pales hairy at base; perennial, stiff-leaved, glaucous sand-grass with creeping rhizome. _Aristida. Sporobolus._

=8.= PHALARIDEÆ. Panicles and spike-like panicles. The spikelet has in the upper part a single fertile flower; below it are placed 4 pales, of which the upper 1–2 sometimes support ♂-flowers. On the whole, 6 floral-leaves of the first order are present.--_Phalaris_ (_P. canariensis_, Canary-grass) has an ovate, spike-like panicle, the spikelets are compressed, convex on the outer side, concave on the inner. The large glumes are winged on the back.--_Digraphis_ (_D. arundinacea_) is closely allied to _Phalaris_, but the keel of the glumes is not winged.--_Anthoxanthum_ (_A. odoratum_, Sweet-vernal) has a small, lanceolate, open, spike-like panicle; the spikelets have below 2 barren flowers, and above these an ☿-flower with 2 stamens. The upper glume is longer than the flower.--_Hierochloa._

=9.= CHLORIDEÆ. The spikelets are arranged in the form of a
spike in two rows on one side of an often flatly-compressed
axis; they are mostly 1-flowered.--_Chloris_; _Ctenium_;
_Cynodon_; _Eleusine_; _Microchloa_.

=10.= PANICEÆ. The spikelets are borne in panicles or spikes,
which may be arranged like fingers or in a raceme. There
is a centrally-placed ☿-flower; below it is sometimes a
♂-flower.--_Panicum_; _Paspalum_; _Oplismenus_; _Setaria_ has
an almost cylindrical spike-like panicle with several barren
branchlets, which project as stiff, rough bristles.--_Cenchrus_;
_Pennisetum_.

=11.= HORDEÆ. Spikes compound; spikelets sessile in the notches of a toothed axis.

=A.= Spikelets solitary.--_Triticum_ (Wheat, Fig. 287) has in each tooth of the main axis, a several-flowered spikelet which turns its _flat side_ towards the central axis. The cultivated species (true Wheat) are 1-2-annual, the wild ones (_T. repens_, Couch, also as an independent genus, _Agropyrum_) are perennial, with creeping rhizome and lanceolate glumes.--_Lolium_ (Rye-grass) has in each tooth of the main axis a many-flowered, compressed spikelet, which is placed _edgewise_ towards it and (with the exception of _L. perenne_) has only one outwardly-turned glume (_L. temulentum_ has a rudiment of the inwardly-turned lower glume); the terminal spikelet has two glumes.--_Secale_ (Rye). A two-flowered spikelet in each tooth; small, lanceolate, acuminate glumes. _Nardus_ and _Lepturus_ have very narrow spikes, the former with unilateral spikelets.

=B.= In each notch of the axis 2 or more spikelets are placed close together.--_Hordeum_ (Barley). In each tooth three 1-flowered spikelets. _H. hexastichum_ (6-rowed Barley), has 6 rows of fruits, since all the spikelets are fertile, and _H. distichum_ (2-rowed Barley) 2 rows, since the lateral spikelets are (♂, and barren (p. 292).--_Elymus_ has 2–6 many-flowered spikelets in each joint of the main axis. _Ægilops_ has awns upon the glumes.

DISTRIBUTION. 315 genera with 3,500 species. The order is
distributed over the whole world, and as regards number of
individuals is perhaps the richest. In the Tropics, large,
broad-leaved, tree-like forms are found (_Bambuseæ_, _Olyreæ_,
_Andropogoneæ_, etc.; in S. Europe, _Arundo donax_); in England,
next to the Compositæ, it is the order most rich in species
(about 134).--The origin of some of the cultivated Grasses
is lost in obscurity. The Maize, no doubt, was indigenous to
America, where its nearest relatives are found, and where it
has also been discovered in ancient Indian graves; Durra or
Guinea-corn, Millet and Sugar-cane are South Asiatic plants, and
our own cereals no doubt have sprung primarily from Western Asia
and South-Eastern Europe (Barley from Armenia and Persia, where
a very closely related wild species is found; Wheat from the
same districts; Rye from the perennial species _S. montanum_).
_Panicum altissimum_ and Rice have come from Africa.

USES. The Grasses play a very important part as cereals and
fodder plants. The following are the most important of the
cultivated ones: _Triticum vulgare_ (common Wheat), _turgidum_,
_amyleum_, _polonicum_, _spelta_, _durum_, etc.; _Secale
cereale_ (Rye); Barley (_Hordeum_-species, see under the genus);
Maize; Oats (_Avena sativa_, _orientalis_, _nuda_); Millet
(_Panicum miliaceum_); Durra (Turkish Millet, or Guinea-corn,
_Sorghum vulgare_, _cernuum_ and _saccharatum_); Manna-grass
(_Glyceria fluitans_). As fodder-plants especially: Rye-grass
(_Lolium perenne_); Oat-grass (_Avena elatior_); Timothy
(_Phleum pratense_); Fox-tail (_Alopecurus pratensis_);
Cock’s foot (_Dactylis glomerata_); Dog’s tail (_Cynosurus
cristatus_); Sweet-vernal (_Anthoxanthum odoratum_); Soft grass,
or Yorkshire-fog (_Holcus lanatus_ and _mollis_); Quaking-grass
(_Briza media_); species of Meadow-grass (_Poa_); Fescue
(_Festuca_) and Brome (_Bromus_).--Several cultivated species of
Grass are also used in the preparation of _fermented liquors_,
the starch in the seeds being transformed to _sugar_ (beer
from “Malt,” _i.e._ the germinated Barley; arrack from Rice);
or the stem becomes specially saccharine before flowering: the
Sugar-cane, _Sorghum saccharatum_.

OFFICINAL. The rhizome of _Triticum repens_, Oat-grain, flour of
Barley, and the starch of Wheat, also sugar.

The seeds of _Lolium temulentum_ are considered
_poisonous_.--The stems of many species (including our common
grains) are used in the manufacture of paper, especially
“Esparto grass” (_Stipa tenacissima_) from Spain and N.
Africa, and the sheathing-leaves of the ♀-spike of _Maize_.
Sand Lyme-grass (_Elymus arenarius_), and especially _Psamma
arenaria_, are important.--But few Grass-species are
_sweet-scented_: _Anthoxanthum odoratum_ and _Hierochloa
odorata_ contain coumarin; _Andropogon_-species have essential
oils (“Citronella oil”).--ORNAMENTAL PLANTS are: the
“Ribbon-grass” (a variety of _Digraphis arundinacea_), _Stipa
pennata_ (whose awn is exceedingly long and feathery), _Gynerium
argenteum_ (Pampas-grass), _Lagurus ovatus_, _Hordeum jubatum_,
_Bromus briziformis_.

Family 3. =Spadicifloræ.=

The primitive form resembles that of the preceding family. In it we find the typical, perfectly developed, Monocotyledonous flower, sometimes even with free carpels and with a dry or somewhat fleshy, but never petaloid perianth; and this passes over into very different forms by the suppression of the floral-leaves, perianth and sporophylls (unisexual flowers are common), and by the close aggregation of the flowers in the inflorescence. The flower is _hypogynous_ in every case. The inflorescence is a _spike_ which may be either single or branched, and has often a thick and fleshy axis (a _spadix_). In Palms and Araceæ it is enveloped, at any rate prior to the opening of the flowers, by a very large floral-leaf, _the spathe_, which may be petaloid (Figs. 297, 301).

The fruit is most frequently fleshy (_berry_, _drupe_) or a _nut_, never a capsule. The embryo is small, with large, fleshy endosperm (Fig. 299 _C_); very rarely the endosperm is wanting.

The numerous plants belonging to this family are large, herbaceous or tree-like, and the leaves seldom have the usual Monocotyledonous form, _i.e._ linear with parallel venation, but most frequently have pinnate or palmate venation.

Order 1. =Palmæ (Palms).= The majority are trees with an _unbranched_, cylindrical _stem_, having short internodes and covered with leaf-scars or the bases of the leaf-stalks (Fig. 296), and at the summit a rosette of large leaves closely packed together (Fig. 295). An exception to this is found in _Calamus_ (Cane, “Rotang”), whose thin, creeping or climbing stems have long internodes; sparsely[28] branched is, _e.g._ the African Doum-palm (_Hyphæne_). Notwithstanding their often enormous stems the Palms have fibrous roots, like the bulbous Monocotyledons. The leaves are pinnate (Feather-palms, Fig. 298) or palmate (Fan-palms, Fig. 295) and often very large; they have a well-developed petiole with an _amplexicaul sheath_, which is often more or less separated into a large number of fibres. _In the bud the blade is entire but folded_, as the leaf expands the lines of folding are torn, either those which are turned upwards (thus ∨ ∨ ∨ ∨, _e.g. Pritchardia_, _Livistona_, _Phœnix_, _Chamærops_) or those turned downwards (thus ∧ ∧ ∧ ∧, _e.g. Cocos_, _Chamædorea_, _Calamus_). The inflorescence is usually lateral; when, as in Sago-palm (_Metroxylon rumphii_) or Talipot (_Corypha umbraculifera_) it is terminal, the plant is monocarpic, and dies after flowering; it is often a very _large_ and _branched spadix_ with numerous flowers either borne externally or embedded in it, and enclosed either in one woody, boat-shaped _spathe_ (Fig. 297) or several spathes, in the latter case one for each branch. The flowers are sessile or even embedded, regular, generally _unisexual_ (monœcious or diœcious) with the usual diagram (Fig. 278); the perianth is inconspicuous, green or yellow, persistent, and more or less leathery or fleshy. 6, rarely 3 or many stamens. The 3 carpels remain either _distinct_ or form one, generally 3-locular, ovary. The style is short. There is _one ovule in each carpel_. Often during ripening 2 carpels with their ovules are aborted. The fruit is a _berry_, _drupe_ or _nut_, generally one-seeded, with a large horny or bony endosperm with hard thick-walled cells (_e.g._ Date-palm). In some (_e.g._ Cocoanut) it is thin-walled, soft, and oily; in several “ruminate.”

When _germination_ commences in the Cocoanut, Date, etc., the
apex of the cotyledon remains in the seed and developes into
a spongy mass to withdraw the endosperm; in the Cocoanut it
attains a considerable size (Fig. 299 _C_) and assumes the
form of the fruit. The endosperm in the Cocoanut is hollow and
the interior is filled with “milk.” In the Date-palm and the
Vegetable-ivory (_Phytelephas_) the cell-walls of the hard
endosperm serve as reserve material.

=1.= PHŒNICEÆ. _Phœnix_ (Date-palm) has pinnate leaves with channeled leaflets and diœcious flowers with 8 free carpels, of which usually only one developes into a berry with membranous endocarp; the large seed has a deep furrow on the inner side, and horny endosperm.

=2.= SABALEÆ. These have fan-like leaves with channeled segments; flowers ☿ or polygamous, rarely diœcious, with 3 separate or only slightly united carpels, all of which are sometimes developed into fruits (berry or drupe, with thin stone).--_Chamærops_, the Dwarf-palm. The pericarp is externally fleshy, internally more fibrous, and provided with a membranous inner layer. The endosperm is ruminate (that is, the testa is several times deeply folded into the endosperm).--_Sabal_, _Copernicia_, _Livistona_ (Fig. 298), _Thrinax_, _Corypha_, _Brahea_, and others.

=3.= COCOINEÆ. With pinnate leaves. Monœcious inflorescence. The carpels are united into a 3-locular ovary. The fruit is most frequently 1-locular, only 1 of the loculi becoming developed, rarely 3-locular; it is a drupe with a large, fibrous, external layer (_mesocarp_) and most frequently a very hard inner layer (_endocarp_, stone) which has 3 germ-pores, the 2 of these, however, which correspond to the suppressed loculi are closed; internal to the third lies the small embryo (Fig. 299). Endosperm containing abundance of oil. _Cocos_ (the Cocoanut-palm), _Attalea_, _Elæis_, _Acrocomia_, _Bactris_.

=4.= LEPIDOCARYINÆ. The floral-leaves and flowers are borne in 2 rows on the spadix. The carpels are united into one 3-locular ovary; the fruit is coated by a layer of hard, shining, imbricate scales. The majority of the species are thorny, and climb by means of the thorny leaves. Some have fan-like (_Mauritia_), others pinnate leaves (_Raphia_, _Calamus_, _Eugeissonia_, _Metroxylon_; the stems of the latter die after the first flowering).

=5.= BORASSINÆ. Large Fan-palms without thorns, with 3-locular
ovary. Drupe with separate stones. _Latania_ and _Lodoicea_ have
many stamens; _Hyphæne_; _Borassus_ (Palmyra-palm).

=6.= ARECINEÆ. The most numerous group. Feather-palms. Berry.
_Areca_, _Euterpe_, _Oreodoxa_, _Ceroxylon_, _Chamædorea_,
_Geonoma_, _Caryota_ with bipinnate leaves.

=7.= PHYTELEPHANTINÆ. Flowers with rudimentary perianth united
in close capitula. _Phytelephas_ (Vegetable-ivory). _Nipa._

DISTRIBUTION. About 1,100 species are known. In Europe
only the Dwarf-palm (_Chamærops humilis_) is wild (Western
Mediterranean). The Date palm (_Phœnix dactylifera_) belongs
to North Africa and West Asia. Other African genera are
_Hyphæne_ (Doum-palm) and _Elæis_ (_E. guineensis_, Oil-palm).
A large majority of the genera are found in South America and
in the East Indies. The following are AMERICAN:--_Mauritia_,
_Acrocomia_, _Bactris_, _Chamædorea_, _Oreodoxa_, _Euterpe_,
_Attalea_, etc. ASIATIC:--_Metroxylon_, _Calamus_, _Areca_,
_Borassus_, _Lodoicea_ (“Double-cocoanuts,” Seychelles) and
others. The Cocoanut-palm has perhaps an American origin; all
the other species of the same genus being endemic in America;
it is the only Palm found on the coral islands of the Pacific
Ocean, and is also the only one which is common to both
hemispheres.

USES. Palms belong to the most useful plants; they contain no
poison, and are of little medicinal interest, but are largely
employed in the arts and manufactures, the hard timber being
adapted for many purposes on account of the hard tissue in
which the vascular bundles are embedded. “Cane” is the stem
of _Calamus_-species (from India). SAGO is obtained from the
pith of _Metroxylon rumphii_ (Sago-palm, Sunda-Is., Moluccas),
_Mauritia flexuosa_, etc. Sugar-containing sap (“palm wine”) is
obtained from the American _Mauritia vinifera_ and _flexuosa_,
_Borassus flabelliformis_ (Asiatic Palmyra-palm), _Arenga
saccharifera_, etc., by cutting off the young inflorescences,
or by perforating the stem before the flowering (_arrack_ is
distilled from this). _Vascular strands_ for the manufacture of
mats and brushes, etc., are obtained from the outer covering
(mesocarp) of the Cocoanut, and from the detached leaf-sheaths
of _Attalea funifera_ (Brazil) (Fig. 296). WAX is yielded by the
leaves of _Copernicia cerifera_ (carnaueba-wax, Amazon region),
and by the stem of _Ceroxylon andicola_ (palm-wax, Andes);
East Indian _Dragon’s blood_ is from the fruit of _Calamus
draco_; the young buds of many species, especially _Euterpe_,
_Cocos_, _Attalea_, etc., are used as “cabbage.” Palm-oil is
obtained from the oily mesocarp of the plum-like fruits of
_Elæis guineensis_ (W. Africa), and from the seeds, when it is
largely used in the manufacture of soap. EDIBLE FRUITS from the
Date-palm (_Phœnix dactylifera_, Arabia, Egypt, W. Africa), and
the endosperm of the Cocoanut (_Cocos nucifera_). The seeds
and the unripe fruits of the Areca-palm (_Areca catechu_)
are chewed with the leaves of the Betelpeper, principally in
Asia. VEGETABLE IVORY from the hard endosperm of _Phytelephas
macrocarpa_ (S. America.)--Many species are cultivated in
the tropics as ornamental plants, but in this country only
_Chamærops humilis_, _Livistona australis_ and _chinensis_ are
generally grown. In addition to the few just mentioned, many
others are of importance, but these are much the most useful.

Order 2. =Cyclanthaceæ.= This is a small order related to the
Palms (44 species from Tropical America), with fan-like, folded
leaves. The flowers are unisexual and arranged in whorls or
close spirals on an unbranched spadix. Ovary unilocular, ovules
numerous. To this belongs _Carludovica palmata_, whose leaves
are used for Panama hats.

Order 3. =Pandanaceæ= (Screw-pines) is another small order,
forming a transition to the Araceæ. The woody, (apparently)
dichotomous stem is supported by a large number of aerial roots,
which sometimes entirely support it when the lower portion of
the stem has decayed. The leaves are closely crowded together,
and arranged on the branches in three rows, which are often
obliquely displaced, with the formation of three spiral lines;
they are, as in the Bromeliaceæ, amplexicaul, long, linear,
the edge and lower midrib often provided with thorns. The
♂-flowers are borne in branched, the ♀ in unbranched spadices
or capitula, which resemble those of _Sparganium_, but have no
floral-leaves. Perianth absent. The drupes or berries unite into
multiple fruits.--About 80 species in the islands of the Indian
Ocean.--_Pandanus_, _Freycinetia_.--Fossils perhaps in the chalk
of the Harz.

Order 4. =Typhaceæ.= The flowers are unisexual, monœcious, and borne on a cylindrical spike or globose capitulum; ♂ inflorescences above, the ♀ below. The perianth consists of a definite number of scales (_Sparganium_), or in its place numerous irregularly-arranged hairs are found (_Typha_); in the ♂-flower there are generally three stamens; the gynœceum is formed of 1–2 carpels with 1 prolonged style; 1 pendulous ovule. The seeds are furnished with a seed-cover, which is cast off on germination.--The few species (about 20) which belong to this order are marsh plants with creeping rhizome (and hence grow in clusters); the leaves on the aerial shoots are borne in two rows, entire, very long and linear.

_Sparganium_ (Bur-reed). The flowers are borne in globose capitula; the perianth distinct, generally consisting of 3 small scales; pistil bicarpellate. Drupe, dry and woody. ~The stalk of the lower ♀ capitula is sometimes united with the main axis, and consequently the capitula are situated high above their subtending-leaf.~

_Typha_ (Bulrush, Reed-mace) has a long, cylindrical, brown spike, the lower portion bearing ♀-flowers, and the upper ♂-flowers, which is divided into joints by alternate leaves. The ♀-flowers have 1 carpel. The perianth is wanting, represented by a number of fine, irregularly-placed hairs; pistil unicarpellate. Fruit a nut.

The two genera, according to some, are related to the 2nd order.
In both genera native species are found. The pollination is
effected by the wind, and consequently the anthers project
considerably, and the stigma is large and hairy. _Typha_ is
protandrous, _Sparganium_ protogynous. The small, fine hairs
surrounding the nut of _Typha_ assist in its distribution by the
wind.--Fossil _Typhas_ in the Tertiary.

Order 5. =Araceæ= (=Arums=). The flowers are small, and always borne _without bracts or bracteoles_ on _an unbranched_, often very fleshy spike, which is enclosed by a spathe, often petaloid and coloured (Fig. 301). The fruit is a _berry_. Outer integument of the seed fleshy.--The leaves have generally sheath, stalk, and blade with distinctly _reticulate_ venation; they are chiefly cordate or sagittate (Fig. 302), seldom long with parallel venation as in the other Monocotyledons (_Acorus_, Fig. 300). The Araceæ are quite _glabrous_, generally _perennial herbs_ with tubers or rhizomes. Many have latex.--For the rest the structure of these plants varies; for example, while some have a perianth, in others it is wanting; in some the perianth-leaves are free, in others united; some have hermaphrodite flowers, but the majority unisexual (monœcious); some have free, others united stamens; the ovules are orthotropous, anatropous, or campylotropous, erect or pendulous; the ovary is 1–many-locular; some have seeds with endosperm, others without. ~_In habit_ there are great differences. While some, _e.g. Colocasia_ (Fig. 302), have a thick, more or less upright stem, with leaf-scars, but not woody, others are climbers, epiphytic, and maintain themselves firmly by means of adventitious roots, on the stems and branches of trees, or even on steep rocks, _e.g. Philodendron_; the cordate, penninerved leaf is the most common (Fig. 302), but various branched forms appear; the pedate leaves of _Helicophyllum_, _Dracunculus_, etc., are cymosely branched; the leaves of _Monstera deliciosa_, perforated by tearing, should be noticed (the vascular bundles while in the bud grow faster than the tissue between them, causing the latter to be torn, and the leaf perforated). With regard to the anatomical structure, the presence or absence of latex, raphides, resin-passages, groups of mucilage-cells should be noted. Engler makes use of these anatomical peculiarities for a scientific arrangement of the order.~

=A.= ORONTIEÆ, CALAMUS-GROUP. ☿, hypogynous flowers of a completely formed monocotyledonous type (number in the whorls 2, 3, or 4).--_Acorus_ (_A. calamus_, Sweet-flag) has a regular, 3-merous, pentacyclic flower (Fig. 300 _C_, _D_). They are marsh-plants, with creeping rhizome, triangular stem, and long, sword-like leaves (Fig. 300 _A_); the inflorescence is terminal, apparently lateral, being pushed to one side by the upright, sword-like spathe (Fig. 300 _B_).--~_Anthurium_ (Pr2+2, A2+2, G2); _Pothos_; _Orontium_ (unilocular ovary with one ovule), etc.~

=B.= CALLEÆ. Flowers hypogynous, naked, ☿.--_Calla_ (_C. palustris_). All flowers in the spike are fertile, or the upper ones are ♂; 6–9 stamens; ovary unilocular with many basal ovules. Marsh-plants with creeping rhizome and cordate leaves.--_Monstera_, _Rhaphidophora_, etc.

=C.= ARINEÆ. Flowers monœcious, naked, ♂-flowers on the upper, ♀ on the lower part of the spadix.--_Arum_ (Fig. 301). The spadix terminates in a naked, club-like portion (_k_); below this is a number of sessile bodies (rudimentary flowers), with broad bases and prolonged, pointed tips (_b_); underneath these are the ♂-flowers (_m_), each consisting only of 3–4 short stamens, which eject vermiform pollen-masses through the terminal pores; then follow, last of all, ♀-flowers (_f_), each of which consists of one unilocular ovary, with several ovules. Perennial herbs, tuberous, with cordate leaves.--~_Dracunculus_; _Biarum_; _Arisarum_; _Pinellia (Atherurus) ternata_ with leaves bearing 1–2 buds. _Zantedeschia æthiopica_ (_Richardia_, Nile-lily); ♂, 2–3 stamens; ♀ with 3 staminodes, 1–5-locular ovary (S. Africa.)--In some genera sterile flowers are present between the ♂ and ♀ portions of the spadix (_e.g._ in _Philodendron_); in _Ambrosinia_ a lateral, wing-like broadening of the axis of the spadix divides the cavity of the spathe into two chambers, the anterior containing one ♀, and the posterior 8–10 ♂-flowers in two series; in some the stamens in the single ♂-flowers unite and form a columnar “synandrium” (_e.g._ in _Dieffenbachia_, _Colocasia_, _Alocasia_, _Caladium_, _Taccarum_, _Syngonium_). A remarkable spadix is found in _Spathicarpa_; it is united for its entire length, on one side, with the spathe, and the flowers are arranged upon it in rows, the ♀ to the outside, and the ♂ in the middle (_Zostera_ has a similar one).--_Pistia_ similarly deviates considerably, it is a floating water-plant, with hairy, round rosettes of leaves; in it also the spathe and spadix are united; at the base a ♀-flower is borne, which consists of one unilocular ovary, and above several ♂-flowers, each composed of two united stamens.~

BIOLOGY. The inflorescences are adapted for
_insect-pollination_; they are protogynous, since the viscous,
almost sessile stigmas come to maturity and wither before the
pollen, which is generally dehisced by apical pores, is shed;
some pollinate themselves freely by the pollen from the higher
♂-flowers falling upon the ♀-flowers below them, and in some
it is conjectured that the pollination is effected by snails.
The coloured spathe, and the naked end of the spadix (often
coloured) of certain genera function as the coloured perianth in
other orders; during flowering a very powerful smell is often
emitted. _Arum maculatum_ is worthy of notice; small flies
and midges creep down into the spathe, between the sterile
flowers (Fig. 301 _b_), which are situated where the spathe is
constricted, and pointing obliquely downwards prevent the escape
of the insects; in the meantime, the stigmas are in a condition
to receive any pollen they may have brought with them; after
pollination the stigmas wither, and exude small drops of honey
as a compensation to the flies for their imprisonment; after
this the anthers (_m_) open and shed their pollen, the sterile
flowers wither, and the insects are then able to escape, and
enter and pollinate other inflorescences.--In many, a _rise
of temperature_ and evolution of carbonic acid takes place
during flowering; a spadix may be raised as much as 30°C. above
the temperature of the surrounding air.--Again, under certain
conditions, many species absorb such large quantities of water
by their roots that water is forced out in drops from the tip of
the leaf; this may often be observed in _Zantedeschia_.

About 900 species in 100 genera. Home, the Tropics, especially
S. America, India, and the Indian Islands, preferably in shady,
damp forests growing as epiphytes upon trees, and on the banks
of streams. Outside the Tropics few are found. _Acorus calamus_
was introduced into Europe from Asia about 300 years ago; it,
however, never sets any fruit, as the pollen is unfertile. In
England _Arum maculatum_ is a very common plant; this and _A.
italicum_ are the only native species. _Colocasia antiquorum_
comes from Polynesia and the Indian Islands, and also _Alocasia
macrorrhiza_. Fossils in Cretaceous and Tertiary.

USES. Many species have pungent, and even _poisonous properties_
(_e.g. Dieffenbachia_, _Lagenandra_, _Arum_), which are easily
removed by boiling or roasting; the _rhizomes_ of many species
of _Caladium_, _Colocasia_ (_C. antiquorum_, _esculenta_, etc.),
are very rich in starch, and in the Tropics form an important
source of food. An uncommon occurrence in the order is the
highly aromatic rhizome of _Acorus calamus_; this contains
calamus-oil and acorin which are used in perfumery. Many are
ornamental plants, _e.g. Zantedeschia æthiopica_ (South Africa),
generally known as “Calla,” and _Monstera deliciosa_; many other
species are grown in greenhouses.

Order 6. =Lemnaceæ (Duck-weeds).= These are the most reduced form of the Spadicifloræ. They are very small, free-swimming water-plants. The vegetative system resembles a small, leaf-like body (Fig. 303 _f-f_), from which roots hang downwards; this branches by producing a new, similar leaf-like body, which springs from a pocket-like hollow (indicated by a dotted line in the figure) on each side of the older one, at its base (or only on one side). ~The branching is thus dichasial or helicoid (Fig. 303 _A_, where _f, f′, f″, f″′_ indicate shoots of 1st, 2nd, 3rd, 4th generations respectively). The leaf-like bodies are, according to Hegelmaier, leaf-like stems, and thus _Lemna_ has no other leaves than the spathe and the sporophylls; according to the investigations of Engler they are stems whose upper portion (above the “pocket”) is a leaf, which is not sharply separated from the underlying stem-portion. The inflorescence is a very much reduced Araceous-spadix, consisting in _Lemna_ of 1 or 2 stamens of unequal length (1-stamened ♂-flowers), 1 unilocular carpel (♀-flower), and 1 thin spathe (_B_). [The same is found in _Spirodela polyrrhiza_, etc., whose daughter-shoots begin in addition with 1 basal-leaf. _Wolffia arrhiza_, etc., have no roots, no spathe, and only 1 ♂-flower in the inflorescence (Engler).]--On the germination of the seed a portion of the testa is thrown off as a lid, so that an exit is opened for the radicle.--19 species. In stagnant fresh water, both Temp. and Tropical.--In Europe the species are _Lemna minor, trisulca, gibba; Spirodela polyrrhiza_, and _Wolffia arrhiza_, the smallest Flowering-plant.~

Family 4. =Enantioblastæ.=

The flowers in this family are _hypogynous_ and have in part the general monocotyledonous type with 5 trimerous whorls completely developed in a regular hermaphrodite flower, and in part the flowers so much reduced that the type is very difficult to trace. On the one hand the family is well developed and has capitate inflorescences (_Eriocaulaceæ_) and on the other hand it is distinctly reduced (_Centrolepidaceceæ_). This family has taken its name from the fact that the ovule is not, as in the Liliifloræ and nearly all other Monocotyledons, anatropous, but _orthotropous_, so that the embryo (βλάστη) becomes placed _at the end of the seed opposite_ (ἐναντίος) _to the hilum_. Large, mealy endosperm.--The orders belonging to this family are by certain authors grouped with the _Bromeliaceæ_ and _Pontederiaceæ_, etc., into one family, FARINOSEÆ, so named on account of the mealy endosperm, the distinguishing character of the Liliifloræ then being that the endosperm is fleshy and horny.

Order 1. =Commelinaceæ.= The complete Liliaceous structure
without great reductions in the number of whorls, but with
generally few ovules in each loculus of the ovary, is found in
the Commelinaceæ, an almost exclusively tropical order with
about 317 species; herbs, some of which are introduced into
our gardens and greenhouses. The stems are nodose; the leaves
often _clasping_; the flowers are arranged in unipared scorpioid
cymes, often so that they form a zig-zag series falling in
the median line of the bracts, and after flowering they bend
regularly to the right or left, outwards or inwards. They
are more or less _zygomorphic_, particularly in the stamens,
which in the same flower are of different forms or partially
suppressed. The outer series of the _perianth_ is sepaloid,
the inner petaloid, generally violet or blue; the filaments
are sometimes clothed with hairs formed of rows of bead-like
cells (well known for showing protoplasmic movements). Fruit
a trilocular _capsule_ with loculicidal dehiscence (generally
few-seeded); in some a nut. The radicle is covered by an
external, warty, projecting covering which is cast off on
germination.--The abundant raphides lie in elongated cells whose
transverse walls they perforate.--_Commelina, Tradescantia,
Tinantia, Cyanotis, Dichorisandra_.

Order 2. =Mayacaceæ.= This order is closely allied to the
Commelinaceæ. 7 species. American marsh- or water-plants.

In many of the following orders of this family the flowers are
united into compound inflorescences, with which is accompanied a
reduction in the flower.

Order 3. =Xyridaceæ= (50 species). Marsh-plants with radical,
often equitant leaves arranged in 2 rows, and short spikes on
long (twisted) stalks. The flowers, as in the Commelinaceæ, have
sepals (which however are more chaffy) and petals, but the outer
series of stamens is wanting. Capsule (generally many-seeded).

Order 4. =Rapateaceæ.= Marsh-plants with radical leaves, usually
in two rows, and several spikelets on the summit of the main
axis, clustered into a capitulum or unilateral spike. Each
spikelet has numerous imbricate floral-leaves and one flower. 24
species. South America.

Order 5. =Eriocaulaceæ.= The “Compositæ among Monocotyledons,”
a tropical order. The flowers are borne in a _capitulum_
surrounded by an _involucre_, very similar to that of the
Compositæ. The flowers are very small, unisexual, ♂ and ♀
often mixed indiscriminately in the same capitulum; they have
the usual pentacyclic structure; the leaves of the inner
perianth are often connate and more membranous than the outer;
in some the outer series of stamens are suppressed; in each of
the 3 loculi is one pendulous ovule. Capsule. The leaves are
generally radical and grass-like.--335 species; _Eriocaulon_,
_Paepalanthus_, etc., _E. septangulare_ on the west coast of
Scotland, and Ireland, and in North America.

Order 6. =Restiaceæ.= A small, especially S. African and S.
Australian, xerophilous order (about 235 species), which is
quite similar in habit to the Juncaceæ and Cyperaceæ. The
leaves are often reduced to sheaths. The flowers are diœcious,
the perianth as in _Juncus_, but the outer series of stamens
suppressed. The ovary and fruit as in Eriocaulaceæ; the ovary,
however, may be unilocular, and the fruit a nut. _Restio_, etc.

Order 7. =Centrolepidaceæ.= These are the most reduced plants
in the family; small grass- or rush-like herbs. The flowers
are very small, naked. Stamens 1–2, carpels 1–∞. 32 species.
Australia.--_Centrolepis_ (flowers generally ☿ with 1 stamen and
2–∞ carpels).

Family 5. =Liliifloræ.=

The flower is constructed on the general monocotyledonous type, with 5 alternating, 3-merous whorls (Fig. 278), but exceptions are found as in the Iridaceæ (Fig. 279) by the suppression of the _inner_ whorl of stamens; in a few the position in relation to the bract differs from that represented in Fig. 278, and in some instead of the trimerous, di- or tetramerous flowers are found (_e.g. Majanthemum_, _Paris_). Flowers generally _regular, hermaphrodite_, with simple, _petaloid_, coloured perianth (except, for example, Bromeliaceæ); ovary trilocular, generally with 2 ovules or 2 rows of ovules in the inner angle of each loculus (Fig. 304 _C_, _D_). _Endosperm_ always present.--A very natural family, of which some divisions in part overlap each other. The habit varies; the leaves are however long, entire, with parallel venation, except in Dioscoreaceæ (Fig. 313).

In the first orders of this family the flowers are hypogynous,
and in the first of all the styles are free, and the capsule
dehisces septicidally; in the following the flowers are
epigynous and in some reduced in number or unisexual; capsule
with loculicidal dehiscence, or a berry.

HYPOGYNOUS flowers: Colchicaceæ, Liliaceæ, Convallariaceæ,
Bromeliaceæ (in part).

EPIGYNOUS flowers: Amaryllidaceæ, Iridaceæ, Bromeliaceæ (in
part), Dioscoreaceæ.

Order 1. =Colchicaceæ.= The flower (Fig. 304 _A_) is ☿, regular, _hypogynous_, trimerous in all five whorls (6 _stamens_); anthers usually _extrorse_. Gynœceum with 3 _free styles_ (_A, D_); fruit a _capsule with septicidal dehiscence_ (_E_); embryo very small (_F_). The underground stem is generally a corm or rhizome, seldom a bulb.

=A.= VERATREÆ.--_Veratrum_; perennial herbs, stem tall with long internodes and broad, folded leaves; the flowers andromonœcious, with free, widely opening perianth-leaves (Fig. 304 _A_), and globular anthers; inflorescence a panicle.--_Zygadenus, Melanthium, Schœnocaulon, Uvularia, Tricyrtis_.

=B.= TOFIELDIEÆ.--_Narthecium_ and _Tofieldia_ have leaves alternate (arranged in two rows), sword-like and borne in rosettes; racemes or spikes. _Narthecium_ forms an exception to the order by having a simple style and fruit with loculicidal dehiscence; _Tofieldia_ by the introrse anthers. In this they are related to the Liliaceæ. _Narthecium_ has poisonous properties, like many other Colchicaceæ.