25. Rottboellia, _Linn. f._
These are tall, annual or perennial gra.s.ses, with leafy stems and narrow leaves. The spikes are few or many, solitary or panicled, with a jointed usually fragile rachis; the joints are rounded or compressed, hollowed on one side and excavated at the tip. The spikelets are usually binate, one-sessile closing or sunk in the cavity of the joint and the other pedicelled, smaller than the sessile or rudimentary with the pedicel usually adnate to the joints and equal to or shorter than it. The sessile spikelets are bis.e.xual, 1- to 2-flowered, equal to or shorter than the joint and four-glumed. The first glume is coriaceous dorsally flattened, obtuse, margins narrowly incurved. The second glume is thinner than the first, broadly ovate, acute and gibbously convex. The third glume is hyaline, ovate, acute, male or neuter, with a membranous palea. The fourth glume is hyaline, bis.e.xual, broadly ovate, acute with a hyaline, ovate-lanceolate palea. There are three stamens with linear anthers. There are two cuneate lodicules. Styles are two with laterally exserted stigmas. The grain is broadly oblong. The pedicelled spikelets are smaller than the sessile, male or neuter, with four glumes. The first glume is herbaceous, many-nerved, ovate-acute, minutely bifid at the apex. The second, third and the fourth are more or less similar to those of the sessile spikelet.
KEY TO THE SPECIES.
Spike solitary, the first glume of the sessile spikelet broadly winged. R. Myurus.
Spikes fascicled, the first glume of the sessile spikelet narrowly winged. R. exaltata.
=Rottboellia Myurus, _Benth._=
This is a tufted perennial with creeping stems which branch freely into ascending compressed branches, 10 inches to 2 feet high.
The _leaf-sheath_ is quite glabrous and compressed. The _ligule_ is a short ciliate membrane. _Nodes_ are glabrous.
_The leaf-blade_ is flat, linear, acute, glabrous, 2 to 6 inches long.
The _inflorescence_ consists of a solitary terminal or axillary _raceme_ 1 to 2 inches long; joints are shorter than the spikelets, excavate on one side and with a pore which is hidden by the sessile spikelet. The _sessile spikelet_ consists of _four glumes_. The _first glume_ is somewhat fiddle-shaped, dilated above the middle into an orbicular wing, and towards the base into two auricles joined by a transverse ridge, scaberulous, 5-nerved. The _second glume_ is somewhat membranous, ovate, acute and 3-nerved. The _third glume_ is hyaline, thin, oblong, obtuse and nerveless. The _fourth glume_ is lanceolate, nerveless and without a palea, bis.e.xual. There are two cuneate _lodicules_. The _pedicelled spikelets_ also have four glumes and the pedicels usually free, but also sometimes adnate. The _first glume_ is oblong, obtuse, winged on one side only, 5-nerved. The _second glume_ is boat-shaped, chartaceous, 3-nerved crested with a semi-circular wing at the apex. The _third glume_ is hyaline, broadly oblong, obtuse, 3-nerved with a lanceolate hyaline palea. The _fourth glume_ is oblong, obtuse, male.
[Ill.u.s.tration: Fig. 144.--Rottboellia Myurus.]
1. A portion of the raceme showing front view; 2. a portion of the raceme showing the back view; 3. a sessile and a pedicelled spikelet showing the front side; 4. the same showing the back side; 5, 6, 7 and 8. the first, second, third and the fourth glume of the sessile spikelet, respectively; 9 ovary and lodicules; 10, 11, 12 and 14. the first, second, third and the fourth glume, respectively, of the pedicelled spikelet; 13 and 15. palea of the third and fourth glumes of the sessile spikelet.
This is very common in dry somewhat sandy places in the East Coast districts.
_Distribution._--Common in Deccan peninsula.
=Rottboellia exaltata, _L.f._=
This gra.s.s is usually annual and rarely perennial. Stems are stout, erect, hispid, branching from the base, varying in height from 3 to 10 feet.
The _leaf-sheaths_ are loose, hispid with tubercle-based hairs, or glabrous, with mouth contracted. The _ligule_ is short and ciliate.
The _leaf-blade_ is linear-lanceolate, setaceously-ac.u.minate with a stout midrib prominent beneath, hispid or scabrid above, smooth or sometimes scaberulous and glaucous beneath, spinulosely scabrid at the margin, 5 to 24 inches by 1/4 to 1 inch.
[Ill.u.s.tration: Fig. 145.--Rottboellia exaltata.
1 and 2. A portion of the spike, back and front view; 3, 4, 5 and 7. the first, second, third and the fourth glume, respectively, of the sessile spikelet; 6 and 8. palea of the third and the fourth glumes of the sessile spikelet; 9. ovary; 10, 11, 12 and 14. the first, second, third and the fourth glume of the pedicelled spikelet; 13 and 15. palea of the third and the fourth glume of the pedicelled spikelet.]
The _racemes_ are stout, cylindrical below and very narrow and with imperfect spikelets above, joints are smooth and rounded dorsally. The _sessile spikelets_ are as long as the joint or slightly shorter and has four glumes. The _first glume_ is ovate-oblong, thickly coriaceous, smooth at the back with a truncate base and a transverse ridge at the base inside, many-nerved, with very narrow inflexed margins and very narrow wings at the top, the apex is obtuse or emarginate. The _second glume_ is equal to the first glume in height, chartaceous, gibbously convex, broadly ovate, acute, 9- to 11-nerved, and with a short wing to the keel at the apex. The _third glume_ is oblong or elliptic-oblong, rigid with a hyaline centre and coriaceous at the sides, 3-nerved, paleate and with three stamens; _palea_ is as long as the glume, coriaceous with inflexed hyaline margins. _Lodicules_ are cuneate, with toothed edge. The _fourth glume_ is a little shorter than the third, ovate from a broad base, hyaline and acute, 1-nerved, paleate and usually with an ovary and two _lodicules_: _palea_ is hyaline, as long as the glume. but narrower, nerveless. _Lodicules_ are quadrate; grain somewhat large oblong and compressed. The _pedicelled spikelets_ are usually imperfect.
This gra.s.s occurs all over the Presidency in cultivated dry fields.
_Distribution._--Throughout the lower hills and plains of India and in Australia and Africa.
26. Mnesithea, _Kunth._
These are erect slender perennial gra.s.ses with narrow leaves. The spikes are solitary and slender, with a fragile, articulated rachis; the joints are terete, ribbed, all but a few upper with two equal and similar sessile spikelets, sunk in sub-opposite oblong cavities, separated by a hyaline septum, and with sometimes a minute glume representing a third spikelet (the pedicelled) on the upper margin of the joint. The sessile spikelets are one-flowered, nearly as long as the internode. There are four glumes in the spikelet. The first glume closing the mouth of the cavity in the joint is obliquely oblong, obtuse, smooth with narrowly incurved margins. The second and the third glumes are as long as the first, obtuse and hyaline. The third glume is empty, paleate or not. The fourth glume is rather small, oblong, obtuse, bis.e.xual and palea shorter than the glume. The lodicules are not present. The stamens are three.
Ovary is very small with stigmas not exserted. The grain is narrowly oblong compressed. The pedicelled spikelets are confined to the upper 1-flowered joints of the spike and their pedicels are confluent with the walls of the joints and their margins are marked by two ribs. The first glume is very minute and the other glumes are absent.
=Mnesithea laevis, _Kunth._=
This is an erect slender perennial gra.s.s with smooth simple or branched stems varying in height from 2 to 4 feet.
The _leaf-sheath_ is terete, tight, glabrous. The _ligule_ is a short toothed membrane. _Nodes_ are glabrous.
The _leaf-blade_ is flat, linear from a narrow base, glabrous or base hairy; apices of upper leaves ac.u.minate, and those of the lower obtuse, with finely serrate margins and a midrib prominent below, 6 to 12 inches long and 1/10 to 1/6 inch wide.
_Racemes_ are short, exserted from the uppermost sheath, erect, 4 to 8 inches long; joints are 1/5 inch long, contracted in the middle, with two equal and similar spikelets, sunk in the opposite oblong cavities separated by a thin hyaline septum and sometimes with a minute glume of the third spikelet on the upper margin of the joint.
[Ill.u.s.tration: Fig. 146.--Mnesithea laevis.
1 and 2. Portions of a spike; 3, 4, 5 and 6. the first, second, third and the fourth glume, respectively; 7. palea of the fourth glume; 8.
ovary; 9 and 10. a part of the spike at the terminal portion.]
The _sessile spikelets_ are 1-flowered, as long as the joint and varying in length from 1/7 to 1/5 inch and have four _glumes_. The _first glume_ is obliquely oblong, coriaceous, smooth, obtuse, margins narrowly incurved, truncate and pitted at the base, 5- to 7-nerved. The _second glume_ is as long as the first hyaline, oblong and obtuse. The _third glume_ is like the second but thinner and slightly broader, paleate or not, empty. The _fourth glume_ is rather smaller than the third, oblong, obtuse, bis.e.xual and paleate; the _palea_ is shorter than the glume.
_Lodicules_ are not present.
This gra.s.s is usually found in dry fields all over the presidency but it is nowhere abundant.
_Distribution._--Throughout India and Ceylon.
27. Manisuris, _Sw._
These are erect leafy much branched annual gra.s.ses. Leaves are amplexicaul and cordate at the base. The inflorescence consists of small, terete, axillary and terminal spikes with peduncles often confluent in a leafy spiciform panicle; the rachis is fragile with short broad joints, deeply excavate opposite the sessile spikelets and the tips with two pits. Spikelets are in dissimilar pairs, one globose, sessile and bis.e.xual and the other ovate, pedicelled, neuter with the pedicels adnate to, or closely appressed to the joint of the rachis. The sessile spikelet has four glumes. The first glume is globose, hard, coa.r.s.ely pitted, with an oblong ventral opening opposite the cavity in the joint of the rachis. The second glume is chartaceous, minute, oblong, 1-nerved immersed in the cavity of the first glume and closing the opening. The third and the fourth glumes are hyaline and minute. The lodicules are broadly cuneate. Anthers are minute. The styles are free and stigmas are short exserted from the opening in the first glume.
Grain is sub-globose.
=Manisuris granularis, _L.f._=
This is a freely branching annual with stems leafy to the top and varying in length from 1 to 2-1/2 feet.
The _leaf-sheath_ is inflated, covered with scattered tubercle-based hairs. The _ligule_ is a short membrane with ciliate margin. _Nodes_ are with long hairs.
The _leaf-blade_ is linear, cordate and amplexicaul at base, acute, flat, flaccid, with scattered tubercle-based hairs on both the surfaces, 4 to 10 inches by 1/4 to 1/2 inch.
The _spikes_ are solitary, axillary and terminal and 1/4 to 1 inch, the peduncles of the spikes are often confluent in a leafy spathiform panicle; the rachis is fragile with short joints deeply excavate on one side.
[Ill.u.s.tration: Fig. 147.--Manisuris granularis.
1 and 2. The front and back view of a bit of a spike; 3, 4, 5 and 6. the first, second, third and the fourth glume, respectively, of the sessile spikelet; 7. ovary anthers and lodicules; 8, 9, 10 and 12. the first, second, third and the fourth glume, respectively, of the pedicelled spikelet; 11 and 13. palea of the third and fourth glumes.]