A Handbook Of Some South Indian Grasses Part 20

[Ill.u.s.tration: Fig. 133.--Ischaemum pilosum.

A and B. Ligules.]

=Ischaemum pilosum, _Hack._=

It is a tall, robust, perennial gra.s.s with rhizomes producing numerous creeping stolons densely covered with scaly-sheaths. The aerial stems are erect, freely branching at the base, slender, 2 to 3 feet long, glabrous.

The _leaf-sheath_ is glabrous. The _ligule_ is a distinct glabrous membrane, 1/8 inch long, rounded. _Nodes_ are glabrous.

The _leaf-blade_ is linear, finely ac.u.minate, glabrous but bearded at the base, 6 to 12 inches long and 1/8 to 1/3 inch broad.

The _inflorescence_ consists of two to six softly hairy spikes which are yellow or brown 1 to 4 inches long. Joints and pedicels are slender, spa.r.s.ely ciliate.

[Ill.u.s.tration: Fig. 134.--Ischaemum pilosum.

1. A sessile and a pedicelled spikelet; 2, 3, 4 and 6. the first, second, third and the fourth glume, respectively, of the sessile spikelets; 5. palea of the third glume, 7. palea of the fourth glume; 8.

ovary; 9, 10, 11 and 12. first, second, third and the fourth glume, respectively, of the pedicelled spikelets; 13. palea of the fourth glume.]

The _sessile spikelets_ are narrowly lanceolate, 3/4 inch long, with long hairs at the base. The _first glume_ is dorsally hairy, or glabrous, narrowed from the middle upwards, chartaceous, with incurved margins and six or seven anastomosing nerves. The _second glume_ is longer than the first, laterally compressed, ovate-lanceolate, ac.u.minate, chartaceous, glabrous but often with long hairs on the keel towards the upper half, 5-nerved, the lateral nerves anastomosing. The _third glume_ is a little shorter than the second, linear-oblong or lanceolate, paleate; _palea_ is membranous, nerveless, and encloses three stamens. The _fourth glume_ is equal to the third glume in length, membranous, hyaline and divided almost to the middle into two acute lobes with an awn 1/4 to 3/8 inch long, paleate; _palea_ is lanceolate, nerveless and encloses three stamens and the ovary and sometimes only the ovary. The _pedicelled_ _spikelets_ are shorter than the sessile but with a shorter awn. The _glumes_ are similar to those of the sessile spikelet; sometimes these spikelets are imperfect or even reduced to a single glume.

This gra.s.s grows well in black cotton soils and sometimes it gets very well established and then it is very difficult to eradicate it. Cattle seem to like this gra.s.s.

_Distribution._--In black cotton soils all over the presidency, but most abundant in the Ceded districts.

[Ill.u.s.tration: Fig. 135.--Ischaemum ciliare.]

=Ischaemum ciliare, _Retz._=

It is a tufted perennial gra.s.s, erect or creeping. Stems are erect or ascending, sometimes dec.u.mbent at base, and rooting at the nodes, stout or slender, 6 inches to 2 feet long.

The _leaf-sheath_ is compressed, loose, glabrous or hairy. The _ligule_ is a short, ciliate membrane. _Nodes_ are glabrous or hairy.

The _leaf-blade_ is flat, linear-lanceolate, ac.u.minate, narrowed towards the acute or rounded base, glabrous or hairy, 2 to 6 inches long and 1/6 to 1/2 inch wide.

The _inflorescence_ consists of two spikes, 1-1/2 to 2 inches long; joints and pedicels of the pedicelled spikelets equal, hairy at the back and at the angles.

The _sessile spikelets_ are 1/8 to 1/5 inch long, oblong, bearded at the base. The _first glume_ is coriaceous, convex, polished, smooth or pitted, hairy below, flat and veined above the middle, with broad or narrow ciliate equal wings and with margins narrowly inflexed above and broadly so below. The _second glume_ is coriaceous, equal to or longer than the first, lanceolate, ac.u.minate, or shortly awned, 3- to 5-nerved, keel narrowly winged towards the apex, dorsally ciliate or not. The _third glume_ is ovate-lanceolate, ac.u.minate, ciliate towards the apex, 1- to 3-nerved, paleate; the _palea_ has a coriaceous lanceolate centre, with broad hyaline ciliate wings and encloses three stamens. The _fourth glume_ is hyaline, deeply lobed into two oblong obtuse glabrous or ciliate lobes, with an awn twice as long as the spikelet in the cleft, and paleate; _palea_ is lanceolate, ac.u.minate, 2-nerved. _Styles_ and _stigmas_ are short.

[Ill.u.s.tration: Fig. 136.--Ischaemum ciliare.

1. Spikelets; 2, 3, 4 and 6. the first, second, third and the fourth glume, respectively, of the sessile spikelet; 5 and 7. palea of the third and the fourth glumes, respectively; 8. lodicules, stamens and the ovary; 9 and 10. the first and the second glumes of the pedicelled spikelet.]

The _pedicelled spikelets_ resemble the sessile ones in the structure of their glumes and palea.

This gra.s.s is very variable in its habit and in the structure of its spikelets. It grows mostly in wet situations, such as the bunds of paddy fields and tanks. Cattle eat the gra.s.s eagerly.

_Distribution._--All over India and Ceylon.

=Ischaemum laxum, _L._=

This is a perennial gra.s.s with numerous stiff, thick and wiry roots.

Stems are erect, slender, rising in tufts from a short root-stock, glabrous, leafy towards the base, varying in length from 2 to 3 feet.

The _leaf-sheaths_ are shorter than the internodes usually glabrous, but occasionally with scattered hairs. At the mouth tufts of hairs are present or not. The _ligule_ is a ridge of silky hairs. The _nodes_ are glabrous.

The _leaf-blades_ are erect, flat, slightly glaucous, linear, narrowed to long capillary tips, 5 to 12 inches long and 1/10 to 1/6 inch broad, with prominent nerves and scabrid margins.

The _inflorescence_ is a solitary spike, 2 to 5 inches long, erect and fragile; the joints and pedicels are compressed, somewhat 2-angled, ciliate with long hairs, and about half as long as the spikelets.

[Ill.u.s.tration: Fig. 137.--Ischaemum laxum.

1. A sessile and a pedicelled spikelet; 2. first glume of a sessile spikelet; 3. second glume of a sessile spikelet; 4 and 5. third and fourth glumes of sessile spikelets; 4a and 5a. are palea of third and fourth glumes; 6. ovary; 7, 8, 9 and 10. glumes of pedicelled spikelets; 9a and 10a. palea of third and fourth glumes.]

The _spikelets_ are in pairs, one-sessile and one-pedicelled. The _sessile spikelets_ are pale-green, linear-oblong, ac.u.minate with a shortly bearded callus, 1/4 to 3/8 of an inch long. There are four glumes in a spikelet. The _first glume_ is chartaceous, oblong-lanceolate, ac.u.minate, 2-toothed with the teeth ending in two short awns, densely ciliated at the apex on one side, conspicuously 6- (rarely) 7-nerved, the two lateral being very strong and running into the apical teeth and the intermediate four nerves being shorter and not running up to the apex, and on the dorsal surface there is a depression, where it is membranous and the nerves on its sides sometimes anastomosing at the upper third of the glume. The _second_ _glume_ is shorter than the first, chartaceous to a certain extent, ovate-lanceolate, ac.u.minate, concave, terminating in a fine scabrid awn, 1/2 inch long, with margins ciliate from above the middle to the apex, and with a narrow ciliated wing on the keel at the apex running up to the base of the awn, 3-nerved. The _third glume_ is lanceolate, ac.u.minate, hyaline, nerveless, ciliate, with a linear obtuse _palea_ enclosing three stamens and two _lodicules_. The _fourth glume_ is hyaline, membranous, deeply split at the apex into two prominent lobes and with an awn in the depression 1/2 inch long, the _palea_ is linear oblong and contains either the ovary alone or both the _stamens_ and the _ovary_.

The _pedicelled spikelets_ are also as long as the sessile, more conspicuous than the sessile and consist of four glumes, but are not awned. The _first glume_ is lanceolate or oblong-lanceolate, chartaceous, with seven strong nerves, very prominent at the back and the mid nerve being most conspicuous, with scabrid keels and closely finely ciliated and folded margins, finely biaristate at the apex. The _second glume_ is lanceolate, finely ac.u.minate, sub-chartaceous, with the margins ciliate from about two-third its length from the apex, 3-nerved, the mid nerve alone being prominent. The _third glume_ is hyaline, nerveless, lanceolate, ciliate in the margin, paleate with 3 stamens or empty. The _fourth glume_ is shorter than the third, hyaline, narrow lanceolate, not awned, ciliate or not at the margin, paleate and with three stamens and two _lodicules_.

This gra.s.s produces a large amount of leaves in good soils and it is liked very much by cattle. It is capable of standing a long spell of dry weather, and is valuable in this respect because it can be depended upon when other gra.s.ses fail. It is worth conserving with other gra.s.ses. It grows both in rich and poor soils, in open places and also in thickets.

_Distribution._--Throughout India and Ceylon.

21. Eremochloa, _Buse._

These are tufted perennial gra.s.ses with rigid equitant leaves at the base. The inflorescence consists of a solitary, glabrous, and compressed spike, with a somewhat fragile rachis; the joints are compressed, hollow and clavate. The spikelets are solitary, usually 2-flowered (rarely 1-flowered), secund, closely imbricating, sessile with a short, pedicelled, reduced upper spikelet, and deciduous with the joint. There are four glumes. The first glume is oblong or ovate, flat, smooth, coriaceous, pectinately margined with upcurved spines. The second glume is oblong-lanceolate, acute and 3-nerved. The third glume is hyaline, obtuse, paleate and male. The fourth glume is smaller, hyaline, oblong, obtuse, 1-nerved, paleate, bis.e.xual or female. Lodicules are truncate and slightly oblique. Stamens are three with long anthers. Styles are two with feathery stigmas. The grain is oval, plano-convex.

=Eremochloa muricata, _Hack._=

This is a perennial tufted gra.s.s with a woody creeping root-stock. Stems are erect or ascending, slender, strongly compressed, lower parts completely covered by rigid equitant leaves, 6 to 18 inches long or more.

The _leaf-sheath_ is broad, flat, much compressed, glabrous and keeled.

The _ligule_ is a short membrane. _Nodes_ are glabrous.

The _leaf-blade_ is linear, glabrous on both sides, 2 to 6 inches long and 3/16 to 1/4 inch broad, with a rounded tip and two unequal lobes.

The _spike_ is solitary, up to 6 inches (or more) in length, joints of the rachis 1/3 to 1/2 the length of the spikelets. _Spikelets_ are solitary, sessile, compressed, secund. The _sessile spikelets_ are 3/16 to 1/6 inch, and consist of four spikelets. The _first glume_ is oblong-lanceolate, dorsally slightly convex, smooth, coriaceous, 7- to 9-nerved, and with pectinate margins consisting of long, spreading, upcurved spines and at the top with subquadrate wings on each side reaching beyond the acute tip. The _second glume_ is chartaceous, oblong-lanceolate, ac.u.minate, usually 5-nerved (and occasionally 3-nerved), the mid-nerve keeled with a narrow wing from below the middle to the base and with hyaline margins. The _third glume_ is oblong-obovate, hyaline, thin, paleate with three yellow _anthers_ and two oblong-cuneate _lodicules_; _palea_ is narrow, oblong, obtuse. The _fourth glume_ is thin, hyaline, oblong-lanceolate, obtuse, paleate, and bis.e.xual; _palea_ lanceolate, narrow, two-toothed at the apex, with deep purple _anthers_ and _stigmas_ of the same colour. The _lodicules_ are obliquely truncate. _Ovary_ has a reddish spot between the style branches and just at the apex in the fresh state in the bud and in the open flower.

[Ill.u.s.tration: Fig. 138.--Eremochloa muricata.

A. Sessile spikelet; B. sessile and a pedicelled spikelet; 1, 2, 3 and 4. the first, second, third and the fourth glume of the sessile spikelet; 3a and 4a. palea of the third and fourth glumes of the sessile spikelet; 5. ovary, anthers and lodicules.]

The _pedicelled spikelet_ is reduced to an inflated body, as long as the sessile spikelet. It is pointed towards both ends, green with anastomosing veins on the outside and membranous, white and nerveless on the other side. The part of the pedicelled spikelet corresponding to the spikelet looks as if the margins of the first and second glumes are confluent all round.