TRIBES II AND III--ORYZEAE AND ZOYSIEAE.
=Oryzeae= is a very small tribe with a few genera, which usually flourish
in marshes. The spikelets are in panicles, 1-flowered and the flower is
usually perfect. In Oryza there are three glumes, the first two being
very minute, and there is only a single glume in Leersia and Hygrorhiza.
There are usually six stamens. The palea becomes firm in texture like
the glume instead of remaining hyaline, and so it is often mistaken for
a glume. The spikelets are jointed on their pedicels and fall away from
them.
Not floating; spikelet not awned 11. Leersia.
Floating; spikelets awned 12. Hygrorhiza.
=Zoysieae= is another small tribe with half a dozen genera. The
inflorescence is either a spike-like raceme or a spiciform panicle. The
spikelets are solitary in Perotis, binate in Tragus and grouped in
Trachys. There is usually a complete flower in a spikelet and the glumes
are membranous. Mature spikelets are deciduous with their pedicels
singly in Perotis and in clusters in others.
Spikelets fascicled unilaterally on a
broad rachis, 4-glumed, glumes not
echinate 13. Trachys.
Spikelets binate and all round the
rachis, 3-glumed, glumes echinate 14. Tragus.
Spikelets single, awned and 3-glumed 15. Perotis.
11. Leersia, _Sw._
These are tall perennial marsh grasses. The inflorescence is usually a
more or less contracted panicle with very slender branches. The
spikelets are compressed and consist of only one glume bearing a perfect
flower. The solitary flowering glume is chartaceous, awnless, 3- to
5-nerved, the lateral nerves forming the thickened margin of the glume.
The palea is narrow, linear-lanceolate, as long as the glume, 3-nerved,
rigid, dorsally ciliate, and with hyaline margins. Lodicules are two.
Stamens are usually six in number. Styles are short, with plumose
stigmas and laterally exserted. Grain is ovoid or oblong, compressed,
free within the glume and its palea.
=Leersia hexandra, _Sw._=
This is a slender perennial marsh-grass with stems rooting in the mud
and with flexuous floating branches, sending up erect or ascending, weak
and slender leafy branches, 2 to 4 feet high.
[Illustration: Fig. 119.--Leersia hexandra.
1. Erect branch; 2 and 3. bits of leaves with ligules; 4 and 5.
spikelets; 6. ovary and lodicules.]
The _leaf-sheath_ is smooth, glabrous, with eciliate margins. The
_ligule_ is a short obliquely truncate or two-lobed membrane. _Nodes_
are hairy with deflexed hairs.
The _leaf-blade_ is flat, narrow, linear, tapering to a fine point,
suberect and rather rigid, glabrous and with a narrow base, varying in
length from 3 to 10 inches and 1/8 to 1/3 inch in breadth.
The _inflorescence_ is an oblong laxly branched, narrow pedunculate
panicle, 2 to 4 inches long.
The _spikelets_ are all 1-flowered and 1-glumed, articulate on the
pedicels above the rudimentary glumes, strongly laterally compressed.
The _glume_ is about 1/6 inch long, ovate-oblong, somewhat boat-shaped,
acute and shortly mucronate, strongly keeled, ciliate on the keel and
margins, 5-nerved, the lateral nerves forming a thickened margin;
_palea_ is as long as the glume, linear-lanceolate, subacute, rigid with
membranous margins. _Stamens_ are six and there are two small
_lodicules_. The first two glumes are reduced to an obscure hyaline rim.
This marsh-grass is found in marshy places such as ditches and channels
in paddy fields, ponds and tanks.
_Distribution._--It is found all over India and Ceylon; also in Africa,
America and Australia.
12. Hygrorhiza, _Nees._
These are floating glabrous grasses with stems diffusely branching and
profusely rooting at the nodes. The inflorescence is a panicle. The
spikelets are 1-flowered, with a solitary flowering glume only. The
flowering glume is awned, strongly 5-nerved, nerves scabrid and ciliate,
the lateral nerves being marginal. Palea is 3-nerved, narrow acuminate
with a ciliate keel. Lodicules are suborbicular. There are six stamens
with long slender anthers. Styles are free with plumose stigmas,
laterally exserted. Grain is oblong, narrowed at the base, obtuse, free
within the glume and its palea.
=Hygrorhiza aristata, _Nees._=
This is a floating aquatic grass. Stems are spongy, branching diffusely,
1 foot long, with feathery whorled roots in dense masses at the nodes;
branches are short, erect and leafy.
The _leaf-sheath_ is smooth, inflated, compressed, with ciliate margins.
The _ligule_ is a narrow membrane. _Nodes_ have whorls of roots.
The _leaf-blade_ is linear or ovate-lanceolate, obtuse, glabrous,
glaucous beneath, base rounded or subcordate, 1 to 3 inches long and 1/2
to 3/4 inch broad.
The _inflorescence_ is a panicle, 2 inches long and broad, somewhat
triangular in outline; the _rachis_ and the branches are stiff, slender
and smooth, the lower branches are a little deflexed.
[Illustration: Fig. 120.--Hygrorhiza aristata.
1. Branch; 2. part of a leaf with ligule; 3. spikelet; 4 and 5. glume
and its palea; 6. lodicules and ovary.]
The _spikelets_ are very narrow, sessile or pedicellate, articulated on
the pedicel, 1-flowered and 1-glumed. The _glume_ is about 3/8 inch long
(excluding the awn) and the awn is as long as the glume or slightly
longer, lanceolate, with five strong nerves and the lateral ones forming
thickened margins; the palea is as long as the glume. _Stamens_ are six
and _lodicules_ two.
Found in ponds and tanks.
_Distribution._--All over India and Ceylon.
13. Trachys, _Pers._
These are softly, villous, diffuse annual grasses. The inflorescence
consists of usually two (rarely three) divaricating spikes on a long
peduncle. The rachis is herbaceous, broad flexuous, jointed and bearing
at each joint a solitary globose cluster of two or three perfect
1-flowered glabrous spikelets surrounded by many short spinescent glumes
of imperfect ones. The perfect spikelets are 4-glumed and the glumes are
very unequal. The first glume is minute, tooth-like, nerveless. The
second glume is long, linear-lanceolate, membranous, very acute,
strongly 3- to 5-nerved. The third glume is the largest, obliquely
ovate, or obovate-oblong, cuspidately acuminate, rigidly coriaceous, 9-
to many-nerved, paleate or not, empty. The fourth glume is shorter and
narrower than the lower one, linear-oblong, acuminate, chartaceous,
smooth, dorsally convex, with incurved margins, bearing a bisexual
flower, paleate, palea is hyaline as long as the glume, and the margins
are inflexed below the middle. Lodicules are very minute or wanting.
There are three stamens. The styles are very long with slender stigmas,
exserted at the top of the glume. The grain is oblong, compressed, free
within the glume and its palea.
=Trachys mucronata, _Pers._=
This is a diffusely branching, softly villous annual grass. The stems
are many from the root, 16 to 18 inches long, ascending or decumbent and
prostrate, leafy, glabrous, rooting freely at the lower nodes,
especially when procumbent.
The _leaf-sheaths_ are loose, inflated, hairy or rarely glabrous. The
_ligule_ is a thin membrane, or a ridge of fine closely set hairs.
_Nodes_ are villous.
The _leaf-blade_ is linear-lanceolate to ovate-lanceolate acuminate,
flaccid, softly villous on both the surfaces, margins often crisped,
base rounded, 2 to 6 inches by 1/4 to 1/2 inch.
The _inflorescence_ consists of a long or short, slender, shining
peduncle bearing two or three rigid, flattened, flexuous, jointed
spikes, the rachis is broad, herbaceous, with a flat, broad, closely
nerved wing on both the sides and with a distinct flat midrib and
jointed, each joint bears on the under surface at the articulation, a
solitary, globose cluster of two to three perfect 1-flowered glabrous
spikelets surrounded by many short spinescent glumes of imperfect ones.
The spikes vary in length from 1 to 2 inches and in breadth from 1/10 to
1/6 inch and are glabrous.
The clusters of _spikelets_ are about 1/4 inch in diameter, often
partially sunk, in a concavity of the rachis; the perfect spikelets are
1/5 to 1/4 inch long and the imperfect are shorter.
[Illustration: Fig. 121.--Trachys mucronata.
A and B. The spikelets; 1, 2 and 3. the first, second and the third
glume, respectively; 4. palea of the third glume; 5 and 6. the fourth
glume and its palea; 7. lodicules, ovary and stamens.]
In the perfect spikelet there are four very unequal glumes. The _first
glume_ is minute, tooth-like, triangular or lanceolate, acute,
nerveless, 1/16 to 1/12 inch long. The _second glume_ is elongate,
linear-lanceolate, acute, sometimes ciliate below the middle,
membranous, narrower than the third glume, hyaline, strongly 3-nerved,
1/16 by 1/6 inch. The _third glume_ is 1/5 by 1/8 inch the largest in
the spikelet, broadly and obliquely ovate or obovate, cuspidately acute,
with nine to many green nerves, paleate; the _palea_ is very small,
about 1/20 inch long, oblong, hyaline and rigidly coriaceous. The
_fourth glume_ is much narrower and shorter than the third glume, linear
oblong, acuminate, chartaceous, smooth, dorsally convex, with incurved
margins, bisexual and paleate; the palea is as long as the glume,
acuminate, hyaline, the margins inflexed below the middle, ovate, acute.
_Lodicules_ are minute or absent. _Stamens_ are three with linear
anthers. _Styles_ are very long with slender stigmas. The grain is
oblong, compressed.
This grass grows abundantly in cultivated dry fields and in the sand
near the sea-shore and it is easily recognized by the clusters of
spikelets in the spike.
_Distribution._--The Deccan Peninsula--both in the interior and on the
sea coast.
14. Tragus, _Haller._
These are annual or perennial grasses, with erect or prostrate stems.
Inflorescence is a spiciform raceme, bearing the spikelets in clusters
of 2 to 4. The spikelets are 1-flowered and usually with two glumes.
Sometimes a very minute hyaline lower glume is present. The first glume
is thickly coriaceous, 5-ribbed, oblong-lanceolate, and ribs with long
recurved spines. The second glume is oblong or oblong-lanceolate,
apiculate, chartaceous, 3-nerved and with a perfect flower; palea is as
long as the glume, 2-nerved. Lodicules are broad, cuneate and fleshy.
There are three stamens. Styles are slender and distinct, with narrow
stigmas exserted from the top of the glume. Grain is oblong to
ellipsoidal free within the glume and its palea.
[Illustration: Fig. 122.--Tragus racemosus.]
=Tragus Racemosus, _Scop._=
This plant is a perennial with tufted prostrate or erect stems, rooting
at the nodes freely and densely leafy. The flowering branches are erect
or geniculately ascending and varies from a few inches to about a foot.
The _leaf-sheath_ is short, pale, glabrous, somewhat compressed,
striate, equitant below and upper are longer, terete and green. The
_ligule_ is only a ridge of short, fine hairs. _Nodes_ are glabrous.
The _leaf-blade_ is convolute when young, ovate or ovate-lanceolate,
variable from 1/4 to 2 inches long and 1/10 to 1/6 inch wide, acuminate,
flat or somewhat wavy, glabrous on both the surfaces, rigidly pungent,
densely crowded and distichously imbricate in the lower part of the
stem, base is amplexicaul, and the margin is distantly serrate and
rigidly ciliate.
The _inflorescence_ is a spike-like terminal panicle varying in length
from 3/4 to 2 inches; the _rachis_ is wavy, slender, angular or grooved,
pubescent, the peduncle is striate, pubescent and enclosed by the
leaf-sheath.
The _spikelets_ are arranged in groups of two, facing each other and
appearing like a single spikelet with two equal echinate glumes,
sessile, or obscurely pedicelled on very short, tumid, pubescent
branches.
[Illustration: Fig. 123.--Tragus racemosus.
1. A pair of spikelets; 2, 3 and 4. the first, second and the third
glume, respectively; 5. palea of the third glume; 6. ovary, anthers and
lodicules.]
There are two (rarely three) _glumes_ in the spikelet. The _first glume_
is very minute, hyaline, obtuse and it is very often not present. The
_second glume_ is about 1/8 inch, ovate-lanceolate, acuminate, strongly
3-ribbed with rows of stout, spreading hooked spines along the ribs and
encloses a single floret. The margins of this glume are membranous and
somewhat scaberulous. The _third glume_ is about 1/12 inch, oblong
lanceolate, membranous minutely hairy, 3-nerved and finely pointed at
the apex; the _palea_ is as long as the glume, hyaline, 2-nerved,
lanceolate, subacute and irregularly toothed at the apex. _Stamens_ are
three, with slender filaments, anthers are short, broad and pale yellow.
The style branches are pale and feathery. _Lodicules_ are two, fleshy
and cuneate or subquadrate. The grain is free inside the glume and the
palea, linear oblong, slightly compressed and pale brown, the embryo
occupies about 1/3 the length of the grain.
This is one of the commonest grasses growing everywhere in tufts with
usually prostrate branches. In some situations the branches are erect.
_Distribution._--Plains of India throughout and Ceylon. It is found in
all the warm regions of the world.
15. Perotis, _Ait._
These are slender annual or perennial grasses with short broad leaves.
Inflorescence is a spike or spiciform raceme. The spikelets are
1-flowered, sessile or shortly pedicelled and jointed. There are three
glumes in the spikelet. The first and the second glumes are empty,
subequal, narrowly linear with a strong midrib which is produced into a
long capillary awn. The third glume is very small, hyaline, lanceolate,
acute, 1-nerved and with a perfect flower; palea is small, narrow,
hyaline and nerveless. Stamens are three with short anthers. Styles are
short and united at the base with very short stigmas. The grain is long
and narrow, longer than the flowering glume.
[Illustration: Fig. 124.--Perotis latifolia.]
=Perotis latifolia, _Ait._=
This grass is an annual with slender leafy stems, branching at the base,
prostrate at first and then geniculately ascending, terminating in
inflorescences and varying in length from 3 to 15 inches.
The _leaf-sheaths_ are glabrous, usually all short except the one next
to the inflorescence which is two or three times as long as the lower
sheaths. The _nodes_ are purple and glabrous.
The _leaf-blade_ is short, 1 to 1-1/4 inches long, ovate or lanceolate,
cordate at base, acute and glabrous on both the surfaces; the margin is
minutely serrate, rigidly ciliate and with a very narrow hyaline border.
The _inflorescence_ is a slender, crinite, spike-like raceme, 1 to 8
inches long, with a finely scabrid main _rachis_.
The _spikelets_ are narrow linear 1/12 to 1/8 inch or longer, purple,
shortly pedicelled and 1-flowered, pedicels are short with a hyaline
swelling on the upper side at the base.
[Illustration: Fig. 125.--Perotis latifolia.
1 and 2. Spikelets; 3, 4 and 5, the first, second and the third glume,
respectively; 6. ovary, stamens and lodicules.]
There are three _glumes_. The _first_ and the _second glumes_ are empty,
narrow-linear, purple, scabrid, 1-nerved and awned; awns are capillary,
varying in length from 1/3 to 1/2 inch. The _third glume_ is very minute
with very small palea. There are three _stamens_ and two small
_lodicules_. _Styles_ are somewhat shorter. The grain is long and
cylindric.
This grass grows in open waste places and in dry fields all over the
Presidency.
_Distribution._--Throughout India.