The _hypogynous_ flowers in the Juncaceæ are completely developed on
the _pentacyclic, trimerous_ type, with _dry, scarious perianth_.
Even in these the interior whorl of stamens becomes suppressed, and
the ovary, which in _Juncus_ is trilocular with many ovules, becomes
in _Luzula_ almost unilocular, but still with 3 ovules. The perianth
in the Cyperaceæ and Gramineæ is reduced from hairs, in the first of
these, to nothing, the flowers at the same time collecting more closely
on the inflorescence (spike) supported by _dry_ bracts (_chaff_); the
number of stamens is almost constantly 3; stigmas linear; the ovary
has only 1 loculus with 1 ovule, and the fruit, which is a capsule in
the Juncaceæ, becomes a nut or caryopsis.--The endosperm is large and
floury, the embryo being placed at its lower extremity (Figs. 286 _B_,
291).--The plants belonging to this order, with the exception of a few
tropical species, are annual or perennial herbs. The stems above ground
are thin, and for the most part have long internodes, with linear,
parallel-veined leaves which have long _sheaths_, and often a _ligule_,
_i.e._ a membranous projection, arising transversely from the leaf at
the junction of the sheath and blade. The underground stems are short
or creeping rhizomes. The flowers are small and insignificant. Wind- or
self-pollination.
Order 1. =Juncaceæ= (=Rushes=). The regular, hermaphrodite, hypogynous
flowers have 3 + 3 brown, dry, free perianth-leaves projecting like
a star during the opening of the flower; stamens 3 + 3 (seldom 3 +
0) and 3 carpels united into one gynœceum (Fig. 283); the ovary is
3- or 1-locular; there is as a rule 1 style, which becomes divided
at the summit into 3 stigmas, often bearing branches twisted to the
right (Fig. 283). _Fruit a capsule_ with loculicidal dehiscence. The
embryo is an extremely small, ellipsoidal, cellular mass, without
differentiation into the external organs.
[Illustration: FIG. 283.--Flower of _Luzula_.]
_Juncus_ (Rush) has glabrous foliage-leaves, generally cylindrical,
rarely flat; the edges of the leaf-sheath are free (“_open_”
leaf-sheaths) and cover one another. The capsule, 1- or 3-locular, with
_many_ seeds--_Luzula_ (Wood-Rush) has flat, grass-like leaves with
ciliated edges; the edges of the leaf-sheath are united (“_closed_”
leaf-sheath). The capsule unilocular and _3-seeded_.--_Prionium_: S.
Africa; resembling a _Tacona_.
The _interior_ whorl of stamens, in some species, disappears
partially or entirely (_J. supinus_, _capitatus_,
_conglomerates_, etc.)
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.
[Illustration: FIG. 284.--Diagram of structure of: _A Scirpus
silvaticus_; _B Eriophorum angustifolium_.]
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.
[Illustration: FIG. 285.--_Carex_: _A_ diagram of a male flower;
_B_ of a female flower with 3 stigmas; _C_ of a female flower
with 2 stigmas; _D_ diagrammatic figure of a female flower; _E_
similar one of the androgynous (false) spikelet of _Elyna_. The ♂
is here represented placed laterally; it is terminal, according
to Pax.]
[Illustration: FIG. 286.--_A_ Flower of _Scirpus lacustris_. _B_
Seed of _Carex_ in longitudinal section.]
=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.
[Illustration: FIG. 287.--_Triticum_: _A_ axis (rachis) of ear
showing the notches where the spikelets were inserted; _B_ an
entire spikelet; _C_ a flower with the pales; _D_ a flower
without the pales, showing the lodicules at the base; _E_ glume;
_F_ outer pale; _G_ inner pale; _H_ fruit; _I_ longitudinal
section of fruit.]
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.
[Illustration: FIG. 288.--_Bromus mollis_: _A_ inflorescence; _B_
the uppermost flower of a spikelet, with its axis turned forward;
in front is seen the two-keeled inner pale (bracteole) and the
stamens protrude between this and the outer pale (bract); _C_ an
ovary with the 2 stigmas on its anterior side, the 2 lodicules,
and the 3 stamens; _D_ the fruit seen from the dorsal side; _E_
the same from the ventral side.]
[Illustration: FIG. 289.--Diagrammatic outline of a spikelet: _n
Y_ lower glume; _ø Y_ upper glume; _n I_ upper pale; _ø I_ the
inner pale; _l_-_l_ lodicules; _st_ stamens; _I_-_I_ main axes;
_II_ lateral axes.]
[Illustration: FIG. 290.--Diagram of the Grass-flower: _ni_ outer
pale; _øi_ inner pale; _l_-_l_ lodicules.]
[Illustration: FIG. 291.--Longitudinal section of an Oat-grain:
_a_ the skin (pericarp and testa); _b_ the endosperm; _c_ the
cotyledon; _d_ the plumule.]
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.
[Illustration: FIG. 292.--Barley grain: _A_ section through the
skin (_a-d_) and the most external part of the endosperm; _Gl_
the “aleurone layer”; _st_ starch-containing cells; _B_ starch
grains.]
[Illustration: FIG. 293.--Wheat-grain germinating: _g_ the
plumule; _b_ the first leaf succeeding the cotyledon; _r^1_ the
primary root; _r^2_ lateral root.]
[Illustration: FIG. 294.--Older seedling of the Wheat: _s_ the
second sheathing-leaf; _l_ first foliage-leaf.]
_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_.